Gonococci can be divided into serogroups WI, WII, and WIII by coagglutination. To assess the clinical correlation of serogroups of gonococci, we studied isolates of gonococci from patients with disseminated and uncomplicated gonococcal infections in three cities in the United States. Strains of Neisseria gonorrhoeae belonging to serogroup WI represented 85 (84%) of 101 isolates from patients with disseminated gonococcal infection (DGI) and 68 (40%) of 168 isolates from patients with uncomplicated gonorrhea (P less than .001). The auxotype Arg-, Hyx-, Ura- (AHU) represented 62 (61%) of 101 isolates from DGI and 54 (32%) of 168 isolates from uncomplicated infection (p less than .001); all AHU isolates were serogroup WI. Among other auxotypes, WI strains represented 25 (64%) of 39 isolates from patients with DGI and 14 (12%) of 114 from uncomplicated infections (P less than .001). In Atlanta only, 13 (34%) of 38 isolates from DGI were AHU, but 31 (82%) were serogroup WI (P less than .001). Thus gonococci of serogroup WI are associated with DGI in these cities of the United States, and this correlation appears to be independent of auxotype. Serogroup WI is correlated with serum resistance.