This study reviewed all patients aged 15 years or older with meningococcal disease in Auckland in 1995. Source data included Public Health Service notifications, microbiology laboratory data, and hospitalization and Infectious Disease Unit records. Thirtynine patients were identified, 21 women and 18 men, with a median age of 30 years (range, 18-69 years). Twenty-two (56%) were referred by non-hospital sources, and 17 (44%) presented directly to the hospital. Only 13 (59%) of those 22 patients referred from the community were suspected of having meningococcal disease. Ten of them (78%) received appropriate (3-lactam treatment and had a significantly lower complication rate (1 of 10) than did the rest of the treatment group (12 of 29) (P=.01). Nineteen (50%) were admitted to the intensive care unit, and 12 required ventilation. For 31 patients, blood or cerebrospinal fluid cultures yielded Neisseria meningitidis, 28 of which (90%) were serotype B. Two hospitals treated patients for a mean of 4.8 ± 0.7 days, and the other treated patients significantly longer, for 8.5 ± 0.9 days; there was no difference in outcome. Thirteen individuals (33%) had complications, 11 experienced major events (one death), and eight experienced minor events.