We compared a commercially available PCR assay (Amplicor, Roche, Switzerland) and tissue culture isolation for the detection of C. trachomatis in urethral and/or endocervical swabs. Of the 200 patients studied (130 men and 70 women) PCR and tissue culture gave concordant results in 199 cases; in one case PCR was positive and culture negative. The Amplicor PCR assay proved fast and sensitive and suitable for routine use in most clinical microbiology laboratories.