Susceptibility testing on 302 bacterial strains from 17 different species isolated from clinical sources were performed, in order to compare their susceptibility to a new aminoglycoside recently introduced in the country with 10 of the most common antibiotics in clinical use. The usefullness of this type of study when a new type of antibiotic is introduced in a community is emphasized so the clinicians can have a solid knowledge of its activity on the local bacterial strains.