Objectives: We aimed to study the incidence rate, predictors and outcomes of HIV care interruption (HCI) in Belgium. Methods: We analysed data for adult patients with at least two HIV care records in the Belgian HIV cohort between 1 January 2007 and 31 December 2016. An HCI episode was defined as 1 year without an HIV care record. The HCI incidence rate was analysed using Poisson regression, return to HIV care using a cumulative incidence function with death as a competing risk, and viral load (VL) status upon return to HIV care using logistic regression. Results: We included 16 066 patients accounting for 78 625 person-years of follow-up. The incidence rate of HCI was 5.3/100 person-years [95% confidence interval (CI) 5.1–5.4/100 person-years]. The incidence of return to HIV care after HCI was estimated at 77.5% (95% CI 75.7–79.2%). Of those who returned to care, 43.7% had a VL ≤ 200 HIV-1 RNA copies/mL, suggesting care abroad or suboptimal care (without an HIV-related care record) in Belgium during the HCI, and 56.3% returned without controlled VL and were therefore considered as having experienced a real gap in HIV care; they represented 2.3/100 person-years of follow-up. Factors individually associated with HCI were no antiretroviral therapy (ART) uptake, lower age, injecting drug use, non-Belgian nationality, male gender, not being a man who has sex with men, a shorter time since HIV diagnosis, no high blood pressure and CD4 count < 350 cells/µL. Conclusions: This study highlights the need to investigate return to care and viral status at return, to better understand HCI. Identified predictors can help health care workers to target patients at higher risk of HCI for awareness and support. © 2020 The Authors. HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association