35 episodes of septicemia in 33 patients occurred among 269 consecutive patients with granulocytopenia (granulocyte cell count less than or equal to 0.5 x 10(9)/l) during the 7-year period 1982-1988. 59% of isolated bacteria were Gram-positive (Staphylococcus aureus, Staph. epidermidis, Streptococcus species and Pneumococcus) and 41% Gram-negative (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Enterobacter, Acinetobacter and Citrobacter). Compared to the 7-year period 1975-1981, there was a decrease in the relative number of patients with Gram-negative septicemia. Thus, a shift from a predominating Gram-negative etiology in the 1975-1981 period to a predominating Gram-positive etiology in the 1982-1988 period was noted. In both periods the mortality rate was high in patients with Gram-negative septicemia, especially in patients with a Ps, aeruginosa infection.