Obstructive sleep apnea syndrome (OSA) has been associated with increased cancer incidence and aggressiveness. One hypothesis to support this association is the implication of immune response, particularly the programmed cell death pathway, formed by the receptor PD-1 and its ligand PD-L1. Recent studies have shown a dysregulation of this pathway in severe OSA patients. It has also been shown that small extracellular vesicles (sEVs) carrying PD-L1 induce lymphocytes dysfunction. Thus, the aim of our study was to analyze the expression of PD-L1 on sEVs of OSA patients and to evaluate the role of sEVs on lymphocyte activation and cytotoxicity. Circulating sEVs were isolated from OSA patients and control group. Lymphocytes were isolated from control group. Circulating sEVs were characterized by western blot, nanotracking analysis and flow cytometry, and were incubated with lymphocytes. Our results show no differences in the quantity and the composition of sEVs in OSA patients and no significant effects of sEVs from OSA patients on lymphocyte activation and cytotoxicity. These results suggest that OSA do not modify PD-L1 expression on sEVs, which do not contribute to dysregulation of cytotoxic lymphocytes.