Tibia vara is characterized by inhibited growth of the medial portion of the proximal tibial growth plate, leading to progressive bowleg deformity. Twenty-nine adolescent patients with this condition were reviewed: all were black, 27 (93%) were male, and 19 (66%) had only one side affected. Progressive deformity rather than knee discomfort was the most common presenting complaint. The deformity reportedly developed rapidly during the adolescent growth spurt. The body weights of these patients exceeded the 95th percentile for age and gender by an average of 43 kg. The absence of significant symptoms and a body habitus that obscured the deformity often resulted in delayed diagnosis. Physicians involved in the care of obese black male adolescents should carefully examine them for tibia vara, which has a reported prevalence of 2% to 3% in this population. Treatment options are severely restricted if the condition is not diagnosed early.