38 male patients with obstructive sleep apnea were asked to complete 2 weeks of rating symptoms, physical examination, diagnostic polysomnography, and MMPI testing prior to being placed on nasal continuous positive airway pressure (CPAP) therapy. Six months later, 26 (72.2%) of the 36 subjects available for follow-up showed continued compliance. A regression analysis conducted with those 28 subjects who completed all pretreatment measures showed that continued therapy was predicted by such pretreatment measures as patients' body mass index, ratings of daytime sleepiness and nocturnal sleep quality, and MMPI Depression and Hypochondriasis scale scores (R2 = 0.63). Eventual compliers had a higher Body Mass Index, reported less daytime sleepiness and better nocturnal sleep quality, and scored lower on the MMPI D and Hs scales prior to treatment than did the noncompliers. A linear discriminant function analysis with analog cross-validation showed these five predictors would identify approximately 80% of eventual noncompliers and 97% of those who display compliance. It was concluded that subjective report and personality measures may be useful in predicting long-term use. Additional studies are needed to assess the clinical significance of the noted MMPI scale elevations among sleep apnea patients in general and among those patients who display eventual noncompliance.