In immediate implant-based breast reconstruction (IBBR), large variation is observed in current practices between a direct-to-implant and a two-stage approach (insertion of a breast implant after a tissue expander). This population-based study aimed to compare unplanned short- and long-term revision incidence between direct-to-implant and two-stage IBBR in The Netherlands.All patients who underwent immediate IBBR following a mastectomy between 2015 and 2019 were selected from the nationwide Dutch Breast Implant Registry. Short- and long-term unplanned revision incidences were studied per immediate IBBR, including revision indications and the total number of additional operations. Confounding by indication was limited using propensity score matching.A total of 4512 breast implants (3948 women) were included, of which 2100 (47%) were for direct-to-implant IBBR and 2412 (53%) were for two-stage IBBR. Median (IQR) follow-up was 29 months (range, 16 to 45 months) and 33 months (range, 21 to 47 months), respectively. Short-term revision incidence was 4.0% and 11.7%, respectively (conditional OR, 0.31; 95% CI, 0.23 to 0.42%). Long-term revision incidence was 10.6% (95% CI, 9.2 to 12.1%) and 16.4% (95% CI, 14.8 to 17.9%), respectively. In the propensity score-matched cohort, similar results were found. In the direct-to-implant group, more breasts were reconstructed within the planned number of operations than in the two-stage group.Unplanned revision surgery occurred less often after direct-to-implant IBBR, and more breasts were reconstructed within the planned number of operations compared to two-stage IBBR. These results, based on real-world data, are important for improving patient counseling and shared decision-making.Risk, II.