A substantial proportion of women with the polycystic ovary syndrome (PCOS) are obese and obesity is considered as a prothrombotic state. Platelet-derived microparticles (PMPs) might be implicated in the activation of the coagulation cascade. We aimed to assess plasma PMPs in overweight/obese women with PCOS. We measured plasma PMPs and determined anthropometric, metabolic, hormonal and ultrasonographic features of PCOS in 67 overweight/obese women with PCOS (with body mass index [BMI] >25.0 kg/m²) and in 21 BMI-matched healthy women. Circulating androgens and markers of insulin resistance (IR) were higher in women with PCOS than in controls. Plasma PMPs were also higher in women with PCOS than in controls (p = 0.046). In women with PCOS, plasma PMPs correlated with the mean number of follicles in the ovaries (r = 0.343; p = 0.006). In controls, plasma PMPs did not correlate with any of the studied parameters. In conclusion, plasma PMPs are elevated in overweight/obese women with PCOS compared with BMI-matched controls. The cause of this increase is unclear but both IR and hyperandrogenemia might be implicated. More studies are required to elucidate the pathogenesis of the elevation of PMPs in PCOS and to assess its implications on the cardiovascular risk of these patients.