<i>Background:</i> Continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA) but it is often cumbersome so that adherence to CPAP therapy is limited. <i>Objectives:</i> We evaluated adherence to CPAP therapy after an additional educative intervention in OSA patients after a longer treatment period. <i>Methods:</i> A short patient information program covering many aspects of symptoms, consequences and treatment of OSA was created, and standardized information sessions were developed to be given by an experienced sleep physician to >6,000 participants of patient support group meetings throughout Germany. They also received a booklet containing the essential information of the lectures. Of the 526 randomly selected members of these support groups receiving the anonymized questionnaire by mail, 475 CPAP patients sent the questionnaire back. Of these CPAP patients, 243 participated in a lecture und and had received a booklet (information group) and 232 CPAP patients had not attended a lecture (control group). <i>Results:</i> In the information group, a significantly higher daily usage of CPAP devices (6.9 ± 0.9 h/day) was reported compared with the control group (5.7 ± 1.3 h/day; p < 0.001). Furthermore, the score in the Epworth Sleepiness Scale (ESS) was found to be significantly lower in the information group (median ESS = 6, interquartile range, IQR, 4–8 vs. median = 11, IQR 8–13; p < 0.001). <i>Conclusions:</i> Patients who attended our short information program showed a higher daily usage and a lower subjective daytime sleepiness. These results suggest that patients on CPAP therapy may benefit from education even after a longer treatment period.