Seventeen of 60 cases of pneumococcal bacteremia in children at Baragwanath Hospital in 1983 were caused by strains not fully susceptible to penicillin G. Eight strains had minimal inhibitory concentrations of >1 μg/ml and five were resistant to four or more antimicrobial agents. Only three isolates were resistant to chloramphenicol. Antibiotic-resistant strains occurred in younger children with a mean age of 13.1 months compared with a mean age of 31.6 months in children with susceptible strains (P < 0.01). Underlying conditions, including nutritional status, did not correlate with antibiotic resistance of isolates from blood. Some of the resistant strains were apparently community-acquired. Of 3379 nasopharyngeal swabs taken from hospitalized children 829 yielded pneuoiococei and 408 of these carrier strains were either relatively or fully resistant to penicillin while 241 were resistant to four or more antibiotics. Multiply resistant strains from patients and carriers belonged to serovars 6A, 6B and 19A.