Objective: To describe the associations between overweight measures in childhood and knee pain, stiffness and dysfunction among adults 25 years later. Methods: Subjects broadly representative of the Australian population (n=449, aged 31-41 years, female 48%) were selected from the Australian Schools Health and Fitness Survey of 1985. Height, weight and knee injury were recorded and knee pain was assessed using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC). Childhood height, weight and knee injury had been measured according to standard protocols 25 years earlier and body mass index (BMI) and percentage overweight were calculated. Results: The prevalence of knee pain was 34% and overweight in childhood and adulthood was 7% and 48%, respectively. Overall, there were no significant associations between childhood overweight measures and total WOMAC knee pain, stiffness and dysfunction scores in adulthood. However, in men, overweight in childhood was associated with adulthood WOMAC pain (relative risk (RR) 1.72, 95% CI 1.11 to 2.69) and childhood weight and BMI were associated with WOMAC stiffness and dysfunction. Childhood weight, BMI and overweight were all associated with the presence of adulthood walking knee pain in men and the whole sample. Most of these associations were independent of adult overweight measures. Subjects who were overweight in both childhood and adult life had a significant increase in the risk and prevalence of adulthood walking pain (RR=2.42, 95% CI 1.06 to 5.53). Conclusions: Childhood overweight measures were significantly associated with adulthood knee mechanical joint pain, stiffness and dysfunction among men, independent of adult overweight, suggesting that childhood overweight may lead to later knee symptoms in men. © 2013 BMJ Publishing Group Ltd & European League Against Rheumatism.