Background: The effect of temporal changes in cancer therapy on health status among childhood cancer survivors has not been evaluated. Objective: To compare proportions of self-reported adverse health status outcomes among childhood cancer survivors across 3 decades. Design: Cross-sectional. (ClinicalTrials.gov: NCT01120353) Setting: 27 North American institutions. Participants: 14 566 adults, who survived for 5 or more years after initial diagnosis (median age, 27 years; range, 18 to 48 years), treated from 1970 to 1999. Measurements: Patient report of poor general or mental health, functional impairment, activity limitation, or cancerrelated anxiety or pain was evaluated as a function of treatment decade, cancer treatment exposure, chronic health conditions, demographic characteristics, and health habits. Results: Despite reductions in late mortality and the proportions of survivors with severe, disabling, or life-threatening chronic health conditions (33.4% among those treated from 1970 to 1979 and 21.0% among those treated from 1990 to 1999), those reporting adverse health status did not decrease by treatment decade. Compared with survivors diagnosed in 1970 to 1979, those diagnosed in 1990 to 1999 were more likely to report poor general health (11.2% vs. 13.7%; Plt;0.001) and cancerrelated anxiety (13.3% vs. 15.0%; Plt;0.001). From 1970 to 1979 and 1990 to 1999, the proportions of survivors reporting adverse outcomes were higher (Plt;0.001) among those with leukemia (poor general health, 9.5% and 13.9%) and osteosarcoma (pain, 23.9% and 36.6%). Temporal changes in treatment exposures were not associated with changes in the proportions of survivors reporting adverse health status. Smoking, not meeting physical activity guidelines, and being either underweight or obese were associated with poor health status. Limitation: Considerable improvement in survival among children diagnosed with cancer in the 1990s compared with those diagnosed in the 1970s makes it difficult to definitively determine the effect of risk factors on later self-reported health status without considering their effect on mortality. Conclusion: Because survival rates after a diagnosis of childhood cancer have improved substantially over the past 30 years, the population of survivors now includes those who would have died in earlier decades. Self-reported health status among survivors has not improved despite evolution of treatment designed to reduce toxicities.