Aim: To describe the effects of a summertime pause (SP) in immunoglobulin replacement therapy (IgRT). Patients & methods: We conducted a prospective single-center observational study, including 44 patients undergoing intravenous IgRT between May and June 2019 in a French teaching hospital. Results: IgRT was interrupted in 23 patients from June to October. Patients who underwent an SP were older, more likely to have secondary immunodeficiency (SID) and received lower doses of immunoglobulin and more antibiotics during winter. Most patients who did not undergo an SP had severe primary immunodeficiency. The SP did not increase the risk of infection, improved the quality of life and reduced treatment costs. Conclusion: SP in IgRT is a safe practice and should be considered for patients with mild SID. Lay abstract Immunoglobulin replacement therapy (IgRT) is an expensive treatment used to prevent infections in patients with immunodeficiency. Becauase most of the infections occur during winter, it is sometimes possible to interrupt IgRT during summer. In our study between May and October 2019, the 23 patients who underwent a summertime pause (SP) did not have more infections than the 21 who did not; the former also described an improvement in their quality of life. However, the physicians proposed SP to patients with a specific type of immunodeficiency, with fewer infections during winter and lower doses of IgRT. We report here for the first time the safety and benefits of a summertime pause in IgRT, for selected patients with less severe immunodeficiency. eng< Réduire