OBJECTIVE To determine the efficacy and safety of percutaneous transvenous mitral commissurotomy (PTMC), using multi-track double balloon technique in juvenile mitral stenosis. METHODS Open non-randomised intervention. METHODS Cardiac catheterisation laboratories of The Mater Hospital, The Nairobi Hospital and Kenyatta National Hospital from 1996 to 2001. METHODS Forty five consecutive patients aged less than 21 years with severe pure mitral stenosis and suitable mitral valve apparatus (leaflets, chordae and papillary muscles) for successful commissurotomy. METHODS Percutaneous transvenous mitral commissurotomy under local anaesthesia. Standard left and right heart catheterisation for mitral valve disease. Trans-septal left atrial entry using standard septal puncture technique and left ventricular position secured by super-stiff guide-wire. Double-balloon mitral valvotomy on single guide-wire using multi-track balloon catheters. METHODS Mitral valve area, left atrial pressures, mitral regurgitation grade, NYHA functional class. RESULTS Mitral valve area increased from 0.6 +/- 0.19 cm2 to 1.9 +/- 0.19 cm2 (p<0.001), left atrial pressures from 30.5 +/- 3.9 mmHg to 11.5 +/- 3.8 mmHg (p<0.001). Most patients NYHA functional class immediately improved from class III-IV to class I-II. There was no significant changes in grades of mitral regurgitation or significant complications related to the procedure. CONCLUSIONS PTMC in juvenile mitral stenosis using the multi-track technique is safe and effective yielding satisfactory immediate results.