Patients and gonococcal isolates (n = 783) from five sexually transmitted disease clinics in Ohio and western Pennsylvania were studied to investigate the spread of gonococci with decreased fluoroquinolone susceptibility. Among patients with gonorrhea, rates of infection with strains with decreased fluoroquinolone susceptibility (MIC of 0.125-0.25 μg ciprofloxacin/mL) were 20% for Cleveland, 9% for Akron, 7% for Columbus, 1% for Toledo, and 0.5% for Pittsburgh. Persons infected with strains with decreased susceptibility were more likely than those with susceptible strains to be male and older; no significant differences in sex behaviors, residence of sex partners, or recent antibiotic use were detected. Prevalence of decreased susceptibility was not correlated with reported levels of community fluoroquinolone use. The Pro/IB-3 auxotype/serovar class accounted for 80% (44/55) of isolates with decreased susceptibility. Pro/IB-3 isolates from three cities had indistinguishable pulsed-field gel electrophoresis patterns, suggesting intercity spread of a clone.