OBJECTIVE: To examine the effect of a lifestyle intervention to produce weight loss and increased physical fitness on use and cost of medications to treat cardiovascular disease (CVD) risk factors in people with type 2 diabetes. RESEARCH DESIGN AND METHODS: Look AHEAD is a multicenter randomized controlled trial of 5,145 overweight or obese individuals with type 2 diabetes, aged 45-76 years. An intensive lifestyle intervention (ILI) involving group and individual meetings to achieve and maintain weight loss through decreased caloric intake and increased physical activity was compared with a diabetes support and education (DSE) condition. Medications prescribed to treat diabetes, hypertension, and hyperlipidemia were compared at baseline and 1 year. Medication costs were conservatively estimated using prices from a national online pharmacy. RESULTS: Participants randomized to an ILI had significantly greater improvements in CVD risk parameters and reduced medication use and cost compared with those assigned to DSE. At 1 year, average number of medications prescribed to treat CVD risk factors was 3.1 +/- 1.8 for the ILI group and 3.6 +/- 1.8 for the DSE group (P < 0.0001), with estimated total monthly medication costs of $143 and $173, respectively (P < 0.0001). DSE participants meeting optimal care goals at 1 year were taking an average of 3.8 +/- 1.6 medications at an estimated cost of $194/month. ILI participants at optimal care required fewer medications (3.2 +/- 1.7) at lower cost ($154/month) (P < 0.001). CONCLUSIONS: At 1 year, ILI significantly improved CVD risk factors, while at the same time reduced medication use and cost. Continued intervention and follow-up will determine whether these changes are maintained and reduce cardiovascular risk.