Height at diagnosis has been analyzed in connection with acute lymphoblastic leukemia (ALL). Most prior studies have compared cases to national reference data derived from previous birth cohorts. Our objective was to determine the association of height-for-age Z score (HAZ) at time of diagnosis with the odds ratio (OR) of ALL in a case-control study (N=498) with a contemporaneous population of age-matched, sex-matched, and ethnicity-matched controls. We hypothesized that cases would have greater mean HAZ at time of diagnosis/interview, after adjustment for weight-for-age (WAZ) and weight-for-height (WHZ). HAZ was not associated with ALL. For each 1 SD increase in WAZ the OR of ALL was 0.83 (95% confidence interval [CI], 0.68-0.99). The OR of ALL was increased among children who had either a WAZ ≤−2 (OR, 5.10; 95% CI, 1.85-16.75) or WHZ of ≤−2 (OR, 5.27; 95% CI, 1.65-23.61). Previous findings of taller height among ALL cases may arise from the choice of control populations. Children with low WAZ or WHZ were at increased odds of ALL.