The relationship between acute inflammation and serovar of Chlamydia trachomatis was evaluated in patients with genital chlamydial infection who attended a sexually transmitted diseases clinic. Polymorphonuclear leukocytes (PMNLS) were enumerated on Gram's-stained smears of endourethral contents in men; cervicitis was scored by visual observation of the endocervix in women. Isolates were serotyped with a monoclonal antibody-based radioimmunoassay. The distribution of serovars in 99 women did not differ in the presence or absence of cervicitis or concurrent gonorrhea. An overall difference (P = .037) was observed when serovar distributions in men with less than or equal to 3 PMNLs (n = 42), greater than or equal to 10 PMNLs (n = 41), and gonococcal urethritis (n = 42) were compared. Follow-up pairwise comparisons revealed that men with less than or equal to 3 PMNLs had fewer isolates of serovars F and G than did men with greater than or equal to 10 PMNLs (P less than .05). No strong overall association was observed between inflammation and serovar.