Aminoglycosides are often used in combination with glycopeptides and beta-lactams for the treatment of bacterial endocarditis caused by alpha-haemolytic streptococci, staphylococci and enterococci. Recommendations on dosing and duration of aminoglycoside therapy vary; we detail the laboratory and clinical evidence base for the treatment regimens advised. A number of deficiencies in the published guidelines are highlighted, as is the limited evidence base upon which many of the regimens are recommended. With the increasing use of outpatient treatment of severe infections and once daily administration of aminoglycosides the opportunity should be taken for larger, multicentre clinical trials to evaluate formally both old and new regimens.