Nightmares have been described as the most common form of disturbed dreaming. The definition most widely accepted considers two criteria as definitive elements of nightmares, acute anxiety or fear, and awakening from sleep with full alertness. Contemporary studies suggest that nightmares are relatively common and can either be benign or malignant to the point of being compared to psychosis. Thus when nightmares become frequent and/or recurrent, they tend to become problematic and warrant treatment. The current study aimed to investigate the frequency of nightmares in a large community based sample and trial a brief story line alteration technique. More specifically, the current research was designed to conduct two related studies in order to elucidate nightmare frequency and intensity in an Australian sample and examine the efficacy of self-help nightmare treatments. The main hypotheses in the first study predicted that more than 10% of the sample would report weekly nightmares and significant gender differences in reporting nightmares would be observed. Participants in the first study were 440 university students (115 men and 325 women) aged between 18 and 34 (M = 20.41 years). Participants completed the retrospective metric/s Nightmare Frequency Questionnaire (NFQ) and Pittsburgh Sleep Quality Index (PSQI) and Addendum. The results showed that yearly, monthly and weekly nightmares were common, in particular weekly nightmares. However no significant differences between genders were found. Participants in the second study were 20 students who reported weekly nightmares aged between 18-31 (M = 21.6 years) and completed a battery of retrospective metrics including the Nightmare Effects Survey (NES), Posttraumatic Diagnostic Scale (PDS) and the Profile of Mood States (POMS-37 items). The main hypotheses in the second study predicted that the Storyline Alteration Technique (SLAT) would ameliorate nightmare frequency and waking distress overtime and achieve significantly better therapeutic outcomes in contrast to the Systematic Desensitization (SysD) technique. Results showed that the SLAT was efficacious in significantly ameliorating nightmare frequency overtime and in contrast to the SysD technique. It was concluded that weekly nightmares were more prevalent than previous retrospective findings had indicated and self-help nightmare treatments were efficacious in ameliorating nightmare frequency, associated waking distress and poor sleep.