Thirty cases of bacteremia out of 1512 patients who had been admitted to our Department between February 1988 and June 1991 were reviewed. They consisted of 22 males and 8 females and their age ranged from 32 to 88 years (mean 62.7). 25 of the patients (83.3%) had malignant diseases of which bladder cancer (15 cases) was predominant and 5 had benign diseases. Gram positive bacteria were isolated in 18 cases (56.2%) and fungi in 4 cases (12.5%) from blood culture. Of these MRSA was most prevalent: 6 cases (18.8%), followed by S. epidermidis: 4 cases (12.5%), P. aeruginosa: 3 cases: E. faecalis: 3 cases and Corynebacterium: 3 cases (9.4%). Analysing the onset of bacteremia for each case, in three cases urinary tract infections, in one case a surgical wound infection and in one case a skin infection were prominent before the diagnosis of bacteremia. From their background, 23 cases (76.7%) were so-called compromised hosts. A total of 7 cases had died, 6 cases of bladder cancer and one case of testicular cancer, five of them were on systemic anti-cancer chemotherapy. Of those cases who expired, P. aeruginosa was isolated in two cases, Candida in two cases, MRSA in one case and E. faecium in one case, Corynebacterium in one case. It was noteworthy that in two cases where blood cultures were positive for P. aeruginosa and one case where the blood culture proved positive for Candida, drastic decrease of the peripheral leukocyte number during anti-cancer chemotherapy was seen.(ABSTRACT TRUNCATED AT 250 WORDS)