BACKGROUND: The increase in the prevalence of obesity among children and adolescents in England since the mid-1990s has been dramatic. Cross-sectional evidence suggests ethnic variations in childhood obesity prevalence. OBJECTIVES: The objective of the study was to examine whether and how ethnic variations in childhood overweight/obesity have changed over time, and are affected by socioeconomic factors. METHOD: This study uses logistic regression to analyse ethnic differences in the relative likelihood of being at or above the age- and gender-specific thresholds for overweight and obesity developed by the International Obesity Task Force among children aged between 2 and 15 from 11 ethnic groups included in the Health Surveys for England between 1998 and 2009, adjusting for age, gender, year of data collection and equivalized household income. We separately analyse the likelihood of being at or above the thresholds for overweight (but below those for obesity) and obesity. RESULTS: Trends in overweight/obesity over time among ethnic minority groups do not follow those of white English children. Black African children had higher rates of overweight and obesity, which appear to have peaked, and black Caribbean children had higher rates of obesity than other groups examined, which appear to continue rising. These differences were not explained by socioeconomic variations between groups. CONCLUSION: Policies are required that encourage healthy lifestyles among ethnic minority young people, while engaging with the complexities associated with these choices during childhood and adolescence.