The in-vitro activities of ramoplanin, vancomycin, and teicoplanin against Gram-positive organisms isolated from cancer patients were determined. Ramoplanin was the most active agent tested inhibiting all isolates at a concentration of ≤0.5 mg/L. Although all isolates were also susceptible to vancomycin and teicoplanin, their activities were surpassed by that of ramoplanin. The activity of teicoplanin was moderately better than that of vancomycin against Bacillus cereus, Enterococcus faecium, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus, and most streptococcal isolates, and was comparable to vancomycin for the remainder of the isolates tested.