We used discriminant analysis to examine morphological variation within the Plethodon vandykei species group. Significant differentiation was found among the nine samples used in the study. Canonical discriminant analysis and UPGMA clustering of Mahalanobis' distances among samples revealed morphological divergence of P. vandykei and P. idahoensis. The greatest intraspecific differentiation was found between coastal and Cascade Mountains populations of P. vandykei. Morphological variation within the P. vandykei species group is consistent with protein variation revealed by previous studies. Our results support the long contested taxonomic validity of P. vandykei and P. idahoensis, and indicate that detailed morphometric analyses can be useful in evolutionary studies of Plethodon.