The purpose of this study is to evaluate the usefulness and limitation of Rapizyme CHLAMYDIA, enzyme-linked immunosorbent assay (ELISA) for qualitative detection of anti-chlamydial IgG and IgA antibodies, in the serum of 92 PID patients and 73 pregnant women, compared with those of Sero IPALISA CHLAMYDIA. The result of Rapizyme analysis was obtained within 10 minutes with no special devices. Overall agreements of Rapizyme and Sero IPALISA were 90.9% (IgG) and 90.3% (IgA) in the total patients, 88.0% (IgG) and 85.9% (IgA) in PID patients, and 94.5% (IgG) and 95.9% (IgA) in pregnant women. The positive rate of Chlamydia in PID was 17.4% (16/92). Positive agreement of Rapizyme in Chlamydia positive PID and pregnant women was 100% in both IgG and IgA, and negative agreement was also 100%. Positive agreement in Chlamydia negative PID was 100% in both IgG and IgA, and negative agreement was 90.0% (IgG) and 83.3% (IgA). The results of Rapizyme were in close agreement with those of Sero IPALISA. COI (cut off index) of Sero IPALISA clearly decreased in 3 of 6 PID patients during a 3 to 6 months period after chemotherapy, but those changes were not observed in Rapizyme. These results suggest that Rapizyme CHLAMYDIA is a useful diagnostic kit for Chlamydial PID of outpatients.