We tested McCann's precocity-longevity hypothesis, which proposes that early career achievement is related to premature death, for Major League baseball players (N = 3,760). Age at debut was the definition for precocity. We controlled for possible artifacts of life expectancy selection, the "healthy worker" effect, player position, and body-mass index. Statistically significant Pearson correlations occurred between precocity and longevity, and remained significant when adjusted for artifacts. In a hierarchical multiple regression, every year a baseball player debuted before the average age of 23.6 years was associated with life span being shortened by 0.24 years. The results support the hypothesis that earlier achievement is associated with earlier death. (Contains 1 table.)