This study provides comprehensive data reflecting pertinent denial rates with respect to the medical and general attributes of those airmen denied medical certification in calendar years 1973 and 1974. The study provides such descriptive epidemiologic data as age, sex, occupation, class of certificate applied for, total flying time, and cause-specific annual denial rates for medically disqualified applicants. Eighty-three percent of all denied applicants indicated nonaeronautical occupations. Fifty-three percent indicated less than 40 hours total flying time. The most significant causes for denial (regardless of class applied for) were cardiovascular, the miscellaneous pathology category, neuropsychiatric, and at a substantially lower level, eye pathology.