We report data concerning our experience during three years (1998-2001) about isolation, identification and susceptibility towards antimicrobial agents of coryneform bacteria in infections of hospitalized/at risk patients. We isolated 54 Corynebacterium spp., with prevalence of C. striatum (8 strains) and C. amycolatum (7 strains), and 1 strain of Oerskovia spp. and 1 strain of Actinomyces neuii. 31 strains were isolated from the "exit-site" and 6 from peritoneal fluid of CAPD patients. Vancomycin and teicoplanin were always "in vitro" efficacious. Resistance rates towards other antibiotics were the following: 11% for minocycline, 12.5% for tetracycline, 20% for gentamicin and netilmicin, 61% for erythromycin and chloramphenicol, 66% for penicillin.