Abstract The purpose of this comparative study was to examine differences in sleep disturbance, sleep effectiveness, and sleep supplementation, as measured by the Verran/Snyder-Halpern (VSH) Sleep Scale, according to phase of adolescence as determined by chronological age and gender. Data were collected from 116 early, 116 middle, and 116 late adolescent boys and girls in classroom settings. Two-way analyses of variance (ANOVAs) were used to analyze the data. Three statistically significant findings emerged in the analyses. First, middle adolescents had the highest level of sleep disturbance among the three groups, which was statistically significantly higher than that found in late adolescents. Second, adolescent girls reported less sleep effectiveness than adolescent boys. Third, when the amount of sleep per day was analyzed, findings indicated that adolescent boys slept more than adolescent girls. The discussion of the findings includes implications for nursing research and practice.