The cadherins are a family of calcium-dependent cell adhesion molecules which are thought to be key regulators of morphogenesis. This review contains a discussion of the structure, function and regulation of these cell adhesion molecules. In particular, we discuss recent studies that demonstrate the ability of steroids to modulate cadherin levelsin vivo. We speculate that steroids and estrogenic organochlorines exert their diverse morphoregulatory actions on tissues by altering cadherin levels.