Adenosine deaminase complexing protein (ADCP) immunoreactivity was investigated in 40 ovarian tumors and correlated with clinicopathologic parameters, including tumor steroid receptor content. Ten (29%) of 34 common epithelial ovarian carcinomas showed ADCP reactivity. Reactivity for ADCP was seen more frequently in mucinous (100%; p < 0.001), well-differentiated (73%; p < 0.001) and Stage I (56%; p < 0.05) ovarian carcinomas. Furthermore, tumors that contained high levels of androgen receptors and tumors that did not contain estrogen receptors were more frequently ADCP positive (p < 0.05). However, after stratifying for histologic grade, no correlation between ADCP reactivity and receptor status was found. Determination of ADCP reactivity appears to be of limited value in ovarian cancer.