We performed an open study to compare efficacy and renal toxicity of cephotaxime versus the usual beta lactam plus aminoglucoside treatment of infectious endocarditis. Twenty cases were studied, 10 treated with cephotaxime 4 g/day per 21 days and aminoglucoside for only 10 days. Comparison group received a combination of different beta lactam antibiotic plus aminoglucoside for 21 to 50 days, these patients were under care of nonparticipant physicians. Although cephotaxime treatment was as good as conventional antimicrobial scheme for control of infectious endocarditis, the treatment cost increases, and there is only marginal benefit in regard renal toxicity.