The best management for adolescents with pelvic inflammatory disease (PID) is unclear. This study compared longitudinal behavioral correlates and reproductive health outcomes between adolescents and adults with PID. In this analysis of data from the PID Evaluation and Clinical Health study, adolescents were significantly more likely than adults to have evidence of endometritis and sexually transmitted infection (Neisseria gonorrhoeae /Chlamydia trachomatis) at baseline and 30 days. During the study, 42.7% of patients experienced chronic abdominal pain, 18.6% experienced infertility, and 21.3% had recurrent PID. Adolescents had a shorter time to both recurrent PID and pregnancy compared with adult women.