A serologic survey for rubella and measles immunity was conducted to determine the immunity levels among a nonurban, relatively isolated pediatric population. Among 1,273 students in grades kindergarten through 9, the overall susceptibility rate was 24.3% for rubella and 16.3% for measles. There was significant variation in susceptibility rates among the various grades and schools involved. The susceptibility rates were similar to those found for urban populations. The results indicated that vaccination efforts for the population have been partially successful, but additional effort was needed.