Background: Obstructive sleep apnea (OSA) is common in the general population and especially in the geriatric age group. Nasal continuous positive airway pressure (CPAP) is a highly effective treatment but can be difficult for some patients to use.Objective: We investigated the question if older patients were less compliant with CPAP therapy than younger patients and may not realize its benefits.Methods: We conducted a prospective, non-randomized study comparing use of CPAP in patients over age 65 with patients under age 65. One hundred and seven consecutive patients with a new diagnosis of obstructive sleep apnea were started on therapy with nasal CPAP. We obtained follow-up data on all 107 patients. Compliance with CPAP was assessed by patients subjective report of use and, in a subset of 21 patients, by objective measurement using a microchip installed in the CPAP unit that measures actual hours of use at therapeutic pressure.Results: The percentage of patients using CPAP regularly was not different in the two groups: 70% of patients in the over age 65 group used CPAP regularly vs. 72% of patients under age 65. The over 65 group used CPAP 6.5 nights per week, an average of 6.5 h of use per night. The under 65 group was not significantly different, using CPAP 6.8 nights per week, a mean of 6.7 h of use per night.Conclusion: Patients over age 65 are able to tolerate CPAP as well as patients under age 65.