In recent years, many anthropogenic chemicals occurring in the environment have been shown to mimic the action of endogenous hormones. These endocrine-disrupting chemicals (EDCs) can potentially lead to a host of adverse effects on wildlife, such as the feminization of fish, the lack of reproductive success of some species, birth defects, and the development of physical abnormality. In an attempt to establish the levels of contamination by EDCs in municipal sewage and sludge, we have collected samples in the Toronto area and analyzed them for alkylphenols, alkylphenol ethoxylates and carboxylates, 17ß-estradiol and its metabolites, testosterone, bisphenol A, as well as butyltin species. Previously developed methods using solvent extraction, solid-phase extraction, supercritical fluid extraction, GC/MS, and HPLC determination have been used for such samples. Levels of these chemicals varied from <1 ng/L for 17ß-estradiol in the effluent to nearly 900 µg/L for nonylphenol ethoxylates in the influent. Levels of EDCs in sludge also varied widely from >500 µg/g for nonylphenol to <0.1 µg/g for bisphenol A. The screening of many of the above EDCs has become an integral part of an on-going wastewater quality monitoring program in Toronto.