Eliminating racial/ethnic disparities in health and health care is a national priority, and obesity is a prime target. During the last 30 y in the United States, the prevalence of obesity among children has dramatically increased, sparing no age group. Obesity in childhood is associated with adverse cardio-metabolic outcomes such as hypertension, hyperlipidemia, and type II diabetes and with other long-term adverse outcomes, including both physical and psychosocial consequences. By the preschool years, racial/ethnic disparities in obesity prevalence are already present, suggesting that disparities in childhood obesity prevalence have their origins in the earliest stages of life. Several risk factors during pregnancy are associated with increased risk of offspring obesity, including excessive maternal gestational weight gain, gestational diabetes, smoking during pregnancy, antenatal depression, and biological stress. During infancy and early childhood, rapid infant weight gain, infant feeding practices, sleep duration, child's diet, physical activity, and sedentary practices are associated with the development of obesity. Studies have found substantial racial/ethnic differences in many of these early life risk factors for childhood obesity. It is possible that racial/ethnic differences in early life risk factors for obesity might contribute to the high prevalence of obesity among minority preschool-age children and beyond. Understanding these differences may help inform the design of clinical and public health interventions and policies to reduce the prevalence of childhood obesity and eliminate disparities among racial/ethnic minority children. Adv. Nutr. 3: 73-82, 2012.