OBJECTIVES: We sought to determine the amount of time required for a primary care physician to provide recommended preventive services to an average patient panel. METHODS: We used published and estimated times per service to determine the physician time required to provide all services recommended by the US Preventive Services Task Force (USPSTF), at the recommended frequency, to a patient panel of 2500 with an age and sex distribution similar to that of the US population. RESULTS: To fully satisfy the USPSTF recommendations, 1773 hours of a physician's annual time, or 7.4 hours per working day, is needed for the provision of preventive services. CONCLUSIONS: Time constraints limit the ability of physicians to comply with preventive services recommendations.