Factors related to successful behavioral intervention for individuals with insomnia are not well understood. In this study we employed the Neuroticism, Extraversion and Openness (NEO) Personality Inventory, to predict successful treatment outcome. Two behavioral treatments for insomnia, sleep restriction therapy (SRT) and relaxation training (RT) were employed in 32 elderly insomniacs. Following two baseline weeks, subjects underwent four weeks of individual treatment. Daily telephone call-ins generated data on sleep times and sleep latency. Follow-up occurred three months after the end of treatment. Results indicated that subjects showing the greatest improvement in total sleep time with both treatments were more traditional, conventional and rigid. Improvement in sleep onset latency was unrelated to NEO Scores. SRT appeared to be more effective for increasing total sleep time in these older subjects.