The Madin-Darby canine kidney (MDCK) cell line is a valuable model of epithelial cell function and the role of E (epithelial)-cadherin in MDCK cell activity is well-appreciated. Northern and immunoblot analyses were used here to demonstrate that, in addition to E-cadherin, MDCK cell cultures also express P(placental)-cadherin. Immunocytochemistry was then used to compare the localization and detergent extractability of P- and E-cadherin. While both cadherins were found at areas of cell-cell contact, the relative ease with which P-cadherin could be extracted suggests a weaker anchorage to the actin cytoskeleton than has been demonstrated for E-cadherin, and may correspond to less permanent cell-cell interactions than those attributed to E-cadherin. The co-expression of different cadherins by MDCK cells has not been fully explored and may influence interpretations of MDCK cell function that previously considered only the activity of E-cadherin.