It has been the policy of the Federal Aviation Administration to medically certify individuals, for a variety of flying privileges, who have a medical deficiency or disease, provided it can be determined that such action does not compromise air safety. During recent years, for example, standards have been relaxed with respect to contact lens use and medication allowed for control of hypertension. This descriptive epidemiologic study presents the point prevalence of pathology among active airmen as of January 1, 1984. Data were obtained from active computer files maintained by the Aeromedical Certification Branch of the Civil Aeromedical Institute in connection with the certification program. Cardiovascular, eye, and abdominal pathologies represent the most prevalent medical conditions among active airmen (5.9 percent, 4.4 percent, and 4.0 percent respectively). Hypertension is the most frequently occurring cardiovascular condition. Of particular interest is the current certification of 263 airmen who have undergone coronary artery bypass. Some 324,986 active airmen (45 percent) require correction for some visual deficiency. Of this total, 20,355 are contact lens wearers. History of kidney stones is the most common genitourinary/abdominal finding. Prevalence of pathology among active civil airmen, while still considerably less than among the general population, is increasing due to current and past emphasis on relaxation of regulatory requirements when consistent with safety.