BACKGROUND: The quality of life (QOL) of ovarian cancer patients is often impaired by refractory ascites. Cell-free and concentrated ascites reinfusion therapy (CART) is a palliative treatment for refractory ascites, but adverse events, such as fever, are problematic. Several cytokines have been suggested to be responsible for the adverse events, but they have not been investigated in detail. Thus, we comprehensively analyzed cytokines in ascites fluid (AF) and serum before and after CART to determine the influence of cytokines on the safety and efficacy of CART. METHODS: Thirteen ovarian cancer patients with refractory malignant ascites who underwent CART were enrolled. We comprehensively analyzed 27 cytokines in AF and serum before and after CART. Simultaneously, vital measurements, blood tests, adverse event recordings, and QOL assessments were performed to examine the relationships between the cytokines in AF and serum. RESULTS: Interleukin (IL)-5, IL-6, IL-10, and monocyte chemoattractant protein-1 levels were increased in the concentrated AF and in the serum immediately after reinfusion, but they decreased after 24 h. Body temperature also increased immediately after reinfusion, and decreased after 24 h. The CRP level at 24 h after reinfusion was increased, and was positively correlated with the IL-6 level. A QOL assessment using the Cancer Fatigue Scale revealed significantly lower scores after CART. CONCLUSIONS: The results indicate that the cytokine-induced fever and increased inflammatory response after CART were temporary, and that CART is safe. Additionally, QOL improved after CART. Thus, CART appears safe and effective for treating patients with refractory cancerous ascites.