Polycystic ovary syndrome (PCOS) is associated with increased cardiovascular disease risk. The effect of weight loss on the vascular inflammatory markers plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA), soluble vascular cell adhesion molecule-1 (sVCAM-1) and intracellular adhesion molecule-1 (sICAM-1) is unknown. Overweight women with (n = 14) and without (n = 13) PCOS of comparable age and body mass index undertook an 8-week weight-loss programme. Women with PCOS had elevated PAI-1, sVCAM-1 and sICAM-1 before and after weight loss compared with the controls. For all women, sVCAM-1 (P = 0.026) and sICAM-1 (P = 0.04) decreased with weight loss. Women with PCOS have elevated inflammatory markers, which are partially reduced by weight loss.