METHODS Fifty patients underwent a Ross operation between June 1991 and October 1996. Preoperative diagnosis was: congenital aortic valve disease (31 patients), complex left ventricular outflow tract (LVOT) obstruction (11 patients), outgrowth of a small aortic valve prosthesis (five patients) and valve endocarditis (three patients). Half of the interventions were reoperations. All operations were root replacements. A pulmonary homograft was used in 45 patients. An aorticoventriculoplasty was combined with the root replacement in the 16 patients with LVOT obstruction and a too small aortic valve prosthesis. An enlargement or reduction plasty of the ascending aorta was necessary in seven patients. RESULTS The mean age was 20.9 years (range: 2.5-54 years). The mean follow up was 34.2 +/- 21 months and was 94% complete. Two patients died after 8 days (low cardiac output due to myocardial fibrosis) and 17.4 months (sudden death), respectively, resulting in a survival of 95 +/- 4% at 4 years. Those two deaths occurred in the group of patients undergoing Ross procedure and aorticoventriculoplasty. Two autografts were replaced after respectively 2 days (technical failure) and 44 months (progressive root dilatation) resulting in a reoperation-free incidence of 93 +/- 6% at 4 years. Other postoperative major complications occurred in six patients. All survivors had regular echo-Doppler examination. All autografts except one had a systolic gradient below 10 mmHg at the last examination. Thirty-four autografts had no leak, ten showed grade 1-2 regurgitation. Two patients showed a higher than grade 3 regurgitation: one leak remains stable with normal left ventricular dimensions and function, one autograft was replaced by a mechanical valve. CONCLUSIONS This experience demonstrates that the medium-term results of the Ross procedure are excellent even in complex LVOT obstructions.