L-Carnosine inhibits senescence of somatic cells and displays anticancer activity. Here we analyzed if L-carnosine (20 mM) retards senescence of human peritoneal mesothelial cells (HPMCs) and inhibits progression of ovarian cancer cells.Experiments were performed with primary HPMCs established from patients undergoing abdominal surgery and with three ovarian cancer cell lines: A2780, OVCAR-3 and SKOV-3.L-Carnosine retards senescence of HPMCs plausibly via inhibition of mitochondria-related oxidative stress. Prolonged exposure of HPMCs to L-carnosine prevented senescent HPMC-dependent exacerbation of cancer cell adhesion, migration, invasion and proliferation, which may be linked with decreased secretion of various pro-cancerogenic agents by HPMCs. Cancer cells exposed directly to L-carnosine displayed reduced viability, increased frequency of apoptosis and unaltered proliferation.L-carnosine may be a valuable anticancer drug, especially in the context of prevention and therapy of intraperitoneal ovarian cancer metastasis.