Between August 1987 and November 1988, combined mitral and aortic balloon valvuloplasty was performed in 10 patients (mean age 42 +/- 9 years), all of whom had symptomatic mitral and aortic stenosis. The procedure was performed using a transarterial approach with a multiballoon catheter and an exteriorized intracardiac long guidewire circuit. The procedure could be considered successful in 9 patients where significant increases in the mean mitral (0.97 +/- 0.19 to 1.80 +/- 0.26 cm2) and aortic (0.63 +/- 0.18 to 1.15 +/- 0.32 cm2) areas were achieved. Severe mitral regurgitation that required surgery developed in 1 patient in the following 24 hours. Femoral vascular surgery was necessary in 1 patient. Mid-term follow-up was available in 8 patients for a period averaging 8 +/- 3 months. The 9 patients in whom the procedure was successful showed persistent clinical improvement in functional class, Doppler echocardiography showed 2 cases of aortic restenosis and none of mitral restenosis. Combined mitral and aortic balloon valvuloplasty could be a valid alternative treatment in selected patients with both mitral and aortic rheumatic stenosis. Further experience and long-term hemodynamic follow-up are necessary to define the role of this mode of treatment.