Episodes of septicaemia caused by Gram-positive bacteria in five separate investigations of empirical antibiotic treatment for fever in patients with neoplastic disease have been analysed according to the antimicrobial agents administered and the outcome. The results suggest that the addition of an 'anti-staphylococcal agent', such as co-trimoxazole, vancomycin or teicoplanin, to the standard two-drug regimen (a beta-lactam antibiotic and an aminoglycoside) may be advantageous in improving the prognosis, particularly in Staphylococcus aureus septicaemia.