Within a population of 117 entrants of a practical nursing school, the predictive validity of three California tests, used as screening devices, and age were investigated. The findings indicated that age had a significant positive relationship to success in practical nursing as measured by final theory grades, National League for Nursing Achievement Test scores, licensure examination scores, and the students' clinical performance. A significant positive relationship was also observed between scores on the California Reading Test and three measures of academic success. The California Test of Mental Maturity was predictive of only one criterion, the final theory grade. The California Test of Personality was a poor predictor of academic success and all three tests failed to be predictive of on-the-job performance.