OBJECTIVE Sexual dysfunction is a prevalent problem in obese women with type 2 diabetes. This study examined the effects of intensive lifestyle intervention (ILI) in these women. RESEARCH DESIGN AND METHODSdLook AHEAD is a 16-center, randomized, controlled trial evaluating the health effects of ILI compared with a control group (diabetes support and education [DSE]). The Look AHEAD Sexual Function Ancillary study included 375 female participants at five Look AHEAD sites. Participants completed the Female Sexual Function Inventory (FSFI) and Beck Depression Inventory (BDI), and assessments of weight and cardiovascular risk factors at baseline and 1 year were made. RESULTSdAt baseline, 50% of the 229 participants who reported being sexually active met criteria for female sexual dysfunction (FSD); only BDI score was related to FSD. One-year weight losses were greater in the ILI group than in the DSE group (7.6 vs. 0.45 kg; P , 0.001). Among women with FSD at baseline, those in the ILI group (N = 60) compared with those in the DSE group (N = 53)were significantly more likely to remain sexually active (83 vs. 64%; P,0.008), reported greater improvement in total FSFI scores and in most FSFI domains (P , 0.05), and were more likely to experience remission of FSD (28 vs. 11%; P,0.04) at 1 year. No significant differences between ILI and DSE were seen in women who did not have FSD at baseline. CONCLUSIONSdParticipation in ILI appeared to have beneficial effects on sexual functioning among obese women with diabetes, particularly in those who had FSD at baseline. © 2013 by the American Diabetes Association.