Objectives: Bacterial infections remain one of the main causes of morbidity and death in people living with HIV (PLHIV) in the most recent years. Several studies have demonstrated a protective effect of statins in the primary prevention of bacterial infections in other immunocompromised populations, but this effect remains controversial. The objective of this study was to evaluate the effect of statin use on the occurrence of a first episode of severe bacterial infection (SBI) in PLHIV in the ANRS CO3 Aquitaine cohort between 2000 and 2018. Methods: All individuals included in the prospective ANRS CO3 Aquitaine cohort who had at least two follow-up visits between 2000 and 2018 were included. The primary endpoint was the occurrence of a first episode of bacterial infection leading to hospitalization of ≥48 hours or death. Statin exposure was updated during follow-up. Marginal Cox structural models were developed to consider the potential indication bias and time-dependent confusion. Numerous sensitivity analyses were carried out. Results: In this study 51 658 person-years were followed. The overall incidence of a first episode of SBI was 12.4/1000 person-years. No effect of statins on the occurrence of SBI was demonstrated when subjects were considered on statins throughout their follow-up after treatment initiation (HR = 0.97; 95%CI: 0.75–1.25). The results were similar for the effect of statins on the risk of pneumonia and for all sensitivity analyses. Conclusion: In this large cohort of PLHIV with 18 years of follow-up and a high risk of severe infections, we found no effect of statins on the risk of occurrence of SBI or pneumonia.< Réduire