The relationship between angiogenesis and fibrosis has been demonstrated in several pathological conditions, one of them being schistosomiasis. To observe whether suppression of angiogenesis would interfere with fibrosis, Thalidomide, an anti-angiogenesis drug, was administered during 30 consecutive days to mice with experimental schistosomiasis. Computerized morphometric measurements of fibrosis, and the counting of blood vessels from hepatic schistosomal lesions did not significantly differ when treated animals and their controls were compared at the end of the experiments. These rather unexpected results are presented under the understanding that they may be of interest during further studies on the anti-angiogenesis properties of thalidomide, and the relationship between angiogenesis and fibrosis.