The in vitro antifungal activity of suramin and its combinations with fluvastatin was investigated in this study. Several species belonging to the class Zygomycetes are considered agents of opportunistic human or animal infections. In the present work, 15 fungal isolates representing eight clinically important genera (Absidia, Micromucor, Mortierella, Mucor, Rhizomucor, Rhizopus, Saksenaea and Syncephalastrum) were investigated. The efficiency with which fluvastatin inhibited growth in the presence of suramin (100 microg ml(-1)) was studied. The investigated compounds acted synergistically and additively on the growth when a strain was resistant to suramin and sensitive to fluvastatin; at the same time, antagonistic interactions were detected when strains were sensitive to both agents. In these cases, the growth inhibition effect of suramin was dominant.