A retrospective review of 150 cases of group B streptococcal disease in nonpregnant adults over an 8-year period was performed in a single tertiary-care teaching hospital to determine the incidence, clinical spectrum, and outcome of the disease. Incidence increased from 0.53 cases per 1,000 admissions in the 1993-1994 period to 0.96 cases per 1,000 admissions in 1999-2000 (P=0.013, chi-square test for trend). Bacteremia also increased from 0.15 to 0.42 cases per 1,000 admissions over the same period of time (P=0.005, chi-square test for trend). The mean age of the patients was 61.4 years, and 92% had at least one underlying disease. Bacteremia was detected in 60.9% of patients in whom blood cultures were performed. Fourteen (9.3%) patients died. Factors independently associated with an increased risk of dying were shock at diagnosis (OR, 23.96; 95%CI, 3.44-166.57; P=0.001) and cancer (OR, 4.96; 95%CI, 1.43-17.20; P=0.012). Group B streptococcal disease in nonpregnant adults is on the rise in the hospital investigated, particularly in persons with underlying conditions. The clinical spectrum of the disease ranges from localized to severe bacteremic infections. Shock at diagnosis and cancer are factors independently associated with a higher fatality rate.