Nationally vehicle theft is associated with approximately 40 fatalities per year with an estimated annual cost of one billion dollars. During 2000 - 2001 almost 139,000 motor vehicles (cars, motor cycles, campervans, and trucks) were stolen across Australia. Vehicle theft is an overwhelmingly adolescent male crime yet gender has not been considered in either policy or program initiatives.----- This thesis used Spence's Multifactorial Gender Identity theory to examine the relationships between vehicle theft, offending, and adolescent male gender identity. Four central research questions were posed:----- 1. Is vehicle theft a gendered behaviour, that is, do some adolescent males engage in vehicle theft to create a particular adolescent male gender identity?----- 2. Do vehicle theft offenders engage in other offending behaviours?----- 3. Are these other offences also used to create a particular adolescent male gender identity and----- 4. Will the use of a variety of gender-related scales to measure gender identity support Spence's Multifactorial Gender Identity Theory that gender identity is multifactorial?----- Study One Parts A and B provided the empirical basis for Studies Two and Three. Part A of Study One examined the "maleness" of vehicle theft and two other problem behaviours: problem drinking and traffic offence involvement. Cross-sectional and longitudinal methodologies were used to investigate a representative sample of 4,529 male high school students in relation to vehicle theft, problem drinking, and traffic offence involvement as a novice driver. Results indicated that "maleness" was significantly related to vehicle theft, problem drinking, and traffic offence involvement. Subsequent analyses, based on Jessor's Problem Behaviour Theory, found a significant relationship between vehicle theft offenders and problem drinking. Study One Part B examined the relationship between masculinity as measured by the Australian Sex Role Scale (ASRS) and problem drinking in a rural sample of 1,248 male high school students. Using a cross sectional methodology, Masculine students were more likely than students in the other gender trait groups to report a range of problem drinking behaviours. Contrary to previous research, both socially desirable and socially undesirable masculine traits were significantly related to most problem drinking behaviours.----- Having established significant relationships between "maleness" and vehicle theft and masculinity and the adolescent problem behaviour of underage drinking, Study Two qualitatively examined the perceptions of adolescent males with histories of vehicle theft in relation to "doing masculinity". Using semi-structured interviews, 30 adolescent males, clients of the juvenile justice system were asked "what do you have to do to be a man?" Vehicle theft was clearly identified as a masculine defining behaviour as were other offending behaviours. Overall, participants nominated very traditional behaviours such as having a job and providing financially for families as essential behaviours in "doing masculinity". It was suggested that in the absence of legal options for creating a masculine gender identity, some adolescent males adopted more readily accessed illegal options. Study Two also canvassed the driving behaviour of adolescent males in stolen vehicles. Crash involvement was not uncommon. Speed, alcohol, and the presence of other adolescent males were consistent characteristics of their driving behaviour. Indigenous and non-Indigenous participants were similar in their responses.----- Study Three compared the gender identity of offender and non-offender adolescent males as measured by three gender-related measures: the ASRS, the Toughness Subscale of the Male Role Norm Scale (TSMRNS) and the Doing Masculinity Composite Scale (DMCS). While the ASRS measured gender traits, the TSMRNS measured masculinity ideology. The DMCS was developed from the responses of participants in Study Two and sought to measure how participants "do masculinity". Analyses indicated vehicle theft was endorsed by just over a third of the sample as a masculine defining behaviour. Overall, offenders were again very traditional in the behaviours they endorsed. When compared to non-offenders, offenders were more likely to endorse illegal behaviours in "doing masculinity" while non-offenders were more likely to endorse legal behaviours. Both offenders and non-offenders strongly endorsed having a car and the ability to drive as masculine defining behaviours.----- In relation to gender traits, non-offenders were more likely than offenders to be classified as Masculine by the ASRS. Surprisingly offenders were more likely to be classified as Androgynous. In relation to masculinity ideology, offenders and non-offenders were similar in their results on the TSMRNS however offenders were more likely to endorse beliefs concerning the need to be tough. Overall Indigenous and non-Indigenous offenders were similar in their responses though Indigenous males were more likely to endorse beliefs concerning the need to be tough. Spence's Multifactorial Gender Identity theory was supported in that the relations between the three gender-related measures were significant but low.----- Results confirmed that vehicle theft was endorsed by a minority of participants as a gendered behaviour. Other offending behaviours were also endorsed by some adolescent males as means to create masculine gender identity. Importantly though both offenders and non-offenders endorsed very traditional behaviours in relation to "doing masculinity". The implications for policy and program initiatives include the acknowledgement of gender identity as an important component in relation to vehicle theft and offending and the desire of adolescent male offenders to engage in legal, traditional male behaviours. In the absence of legal avenues however, some adolescent males may use illegal behaviours to create gender identity. Cars and driving also feature as important components of gender identity for both offenders and non-offenders and these needs to be considered in relation to road safety initiatives.