We assessed whether increasing body mass index (BMI) affects health-related quality of life in a group of 38 overweight (BMI 25-30 kg/m(2)) middle-aged (45.9 ± 5.4 years) men, recruited in Auckland (New Zealand). Health-related quality of life was assessed with SF-36v2 at 0, 12, and 30 weeks. Increasing BMI was associated with a progressive reduction in physical component summary score (p = 0.008), as well as lower general health (p = 0.036), physical functioning (p = 0.024), and bodily pain (p = 0.030) scores. Stratified analyses confirmed these findings: participants who were more overweight (n = 19; BMI 27.5-30 kg/m(2)) had poorer physical component summary (p = 0.005), physical functioning (p = 0.040), bodily pain (p = 0.044), and general health (p = 0.073) scores than the less overweight (n = 19; BMI 25-27.5 kg/m(2)). Increasing BMI is associated with a progressive reduction in physical quality of life, even within a relatively narrow BMI range encompassing only overweight middle-aged men.