Concerns exist as to whether the insertion of copper and levonorgestrel-releasing intrauterine devices (IUDs) increases the risk of pelvic inflammatory disease (PID) among women with sexually transmitted infection (STI). We searched the MEDLINE database for all articles published between January 1966 and March 2005 that included evidence relevant to IUDs and STIs and PID. None of the studies that examined women with STIs compared the risk of PID between those with insertion or use of an IUD and those who had not received an IUD. We reviewed indirect evidence from six prospective studies that examined women with insertion of a copper IUD and compared risk of PID between those with STIs at the time of insertion with those with no STIs. These studies suggested that women with chlamydial infection or gonorrhea at the time of IUD insertion were at an increased risk of PID relative to women without infection. The absolute risk of PID was low for both groups (0-5% for those with STIs and 0-2% for those without).