Background: Percutaneous mitral balloon valvuloplasty (PMBV) has been established as an effective and safe treatment modality for symptomatic patients with severe rheumatic mitral stenosis. While Wilkin Score (WS) ≤ 8 are associated with higher rates of procedural success and lower rates of restenosis, higher WS are associated with lower rates of procedural success and higher rates of restenosis. It is well known that platelets have substantial role in thromboembolic complications of rheumatic mitral stenosis and various studies showed that increased platelet (PLT) activity in rheumatic mitral stenosis. The aim of this study was to assess the usefulness of PLT indices as a predictor of restenosis in patients who underwent PMBV. Methods: We retrospectively enrolled 178 consecutive patients who underwent PMBV. Patients were classified into the two groups. Study group (n=21) included patients whom we performed redo PMBV during their follow-up as a result of mitral restenosis following previous PMBV (index procedure) and control group (n=157) included patients whom did not undergo a redo PMBV. PLT indices including PLT count, Platelecrit and mean platelet volume values were evaluated in these groups. Results: In study group, PLT count (210 ± 49 vs. 241 ± 62, p=0.010), PCT [0.203 (0.173-0.230) vs. 0.260 (0.243-0.290), p