A large measles vaccination program in the Albuquerque, New Mexico public schools in 1981, conducted according to US Public Health Service guidelines, was studied to determine rates of pregnancy among adolescent vaccinees. Pre-vaccination counseling of 1,922 clinic attendees prevented seven pregnant girls from being vaccinated. Despite counseling, of 1,913 female vaccinees age 13-18 years old, two were pregnant at the time of vaccination (1.05 preg-