['To examine whether dietary fish oil supplementation reduces development of spontaneous endometriosis-associated adhesions using an established model.', 'Laboratory-based study.', 'Medical center research laboratory. PATIENT(S)/ANIMAL(S): Disease-free women of reproductive age and nude mice.', 'Women were not provided any intervention. Mice were randomized to receive fish oil supplementation or control diet.', 'Experimental endometriosis was established in mice via injection of human endometrial tissue within 16 hours of ovariectomy. Mice were provided standard or menhaden fish oil-supplemented diets for ≥ 2 weeks before initiation of experimental endometriosis and until killing them 1 week later. At necropsy, mice were examined for the presence and extent of adhesions and endometriotic-like lesions. Tissues were excised and morphologically characterized.', 'Adhesions/lesions were reduced in mice provided with dietary fish oil compared with control animals. Leukocytes were more numerous within the adhesions/lesions of the mice maintained on the standard diet compared with animals provided with fish oil. As indicated by staining intensity, collagen deposition was greater at adhesion sites within control mice compared with fish oil-supplemented animals.'] Does dietary fish oil supplementation inhibit formation of endometriosis-associated adhesions in a chimeric mouse model?