This investigation compares the IUD performance of 372 women who had an insertion-related problem (most with moderate or severe pain) and 372 matched women who had no such problem; all women had interval insertion. A woman in the Problem Cohort and her matched counterpart in the Comparison Cohort were inserted with the same IUD type by the same insertor on the same day or on close dates. The six IUD types used by these women were Lippes Loop D, Copper-7, Copper T-200, Copper T-380 Ag, Multiload Copper 250 and Multiload Copper 375. Cumulative gross life-table rates of the pertinent events (accidental pregnancy, expulsion and medical removal for bleeding and pain), adjusted for age and parity, were calculated. Between the Problem Cohort and the Comparison Cohort, no differences were detected in the event rates that were of either statistical or practical significance. Results from this preliminary study suggest that the insertion-related problems usually encountered during interval insertion such as insertion pain, syncope and/or mild cervical laceration are not associated with an increased risk of IUD discontinuation due to pertinent events.