Background: Use of more effective contraception may lead to less condom use and increased incidence of sexually transmitted infection. Objective: The objective of this study was to compare changes in condom use and incidence of sexually transmitted infection acquisition among new initiators of long-acting reversible contraceptives to those initiating non-long acting reversible contraceptive methods. Study Design: This is a secondary analysis of the Contraceptive CHOICE Project. We included two sample populations of 12-month continuous contraceptive users. The first included users with complete condom data (baseline, 3, 6, and 12 months) (long-acting reversible contraceptive users: n=2371; other methods: n=575). The second included users with 12-month sexually transmitted infection data (long-acting reversible contraceptive users: n=2102; other methods: n=592). Self-reported condom use was assessed at baseline and at 3, 6, and 12 months following enrollment. Changes in condom use and incident sexually transmitted infection rates were compared using chi-square tests. Risk factors for sexually transmitted infection acquisition were identified using multivariable logistic regression. Results: Few participants in either group reported consistent condom use across all survey time points and with all partners (long-acting reversible contraceptive users: 5.2%; other methods: 11.3%, P<0.001). There was no difference in change of condom use at 3, 6 and 12 months compared to baseline condom use regardless of method type (p=0.65). A total of 94 incident sexually transmitted infections were documented, with long-acting reversible contraceptive users accounting for a higher proportion (3.9% vs. 2.0%; P=0.03). Initiation of a long-acting reversible contraceptive method was associated with increased sexually transmitted infection incidence (OR 2.0, 95% CI: 1.07, 3.72). Conclusions: Long-acting reversible contraceptive initiators reported lower rates of consistent condom use, but did not demonstrate a change in condom use when compared to pre-initiation behaviors. Long-acting reversible contraceptive users were more likely to acquire a sexually transmitted infection in the 12 months following initiation.