A nationwide reconnaissance investigation was initiated in 1994 to develop and evaluate a suite of reproductive and endocrine biomarkers for their potential to assess reproductive health and status in teleost (bony) fish. Fish collections were made at 119 sites, representing many regions of the country and land- and water-use settings. Collectively, this report will provide a national and regional benchmark and a basis for evaluating biomarkers of endocrine and reproductive function. Approximately 2,200 common carp (Cyprinus carpio) and 650 largemouth bass (Micropterus salmoides) were collected from 1994 through 1997. The suite of biomarkers used for these studies included: the plasma sex-steroid hormones, 17?-estradiol (E2) and 11 ketotestosterone (11KT); the ratio of E2 to 11KT (E2:11KT); plasma vitellogenin (VTG); and stage of gonadal development. This data report provides fish size, stage and reproductive biomarker data for individual fish and for site and regional summaries of these variables.