Objective: To assess the construct validity of a milk consumption Stages of Change (SOC) algorithm among adolescent survivors of childhood cancer ages 11 to 21 years (n = 75). Methods: Baseline data from a randomized controlled trial designed to evaluate a health behavior intervention were analyzed. Assessments included a milk consumption SOC algorithm and hypothesized theoretical and behavioral predictors of SOC. Results: Compared with survivors who expressed no readiness to change, those expressing readiness to change behavior for both 2 and 4 daily servings of milk reported more frequent milk consumption (P less than 0.001), greater dietary calcium intake (P = 0.006), and were more likely to meet age-specific recommendations for daily calcium intake (P = 0.01). Conclusions and Implications: Results provide support for the construct validity of the milk consumption SOC algorithm relative to behavioral criteria. Research is needed to further examine algorithm validity with respect to theoretical predictors of SOC. (Contains 1 figure and 1 table.)