We examined survival in childhood acute lymphoblastic leukemia (ALL) as a function of season-of-treatment initiation. Survival for 1797 children aged 15 and under from the Surveillance, Epidemiology, and End Results (SEER) cancer registry, diagnosed and treated from 1973-1986 was obtained. There was no significant seasonal pattern for survival by season-of-treatment initiation. Neither age, gender, nor treatment type served as effect modifiers or confounders in this relationship. Female gender, age between one and ten years, and certain broad categories of treatment type were significant predictors of survival in separate univariate analyses, however. The nonsignificance of the results do not support the concept that season-of-treatment initiation is a prognostic factor in survival from ALL in children.