Weasels and mink (Mustela and Neogale) can be difficult to distinguish osteologically due to similarities in morphology, thus suggesting the need for an accurate tool in distinguishing among taxa. This study utilized a combination of character state and stepwise discriminant function (DFA) analyses to examine potential distinguishing features of skull and tooth morphology. Measurements and ratios were collected from all 18 extant musteline species, as well as the extinct Neovison macrodon, Mustela rexroadensis, Mustela meltoni, Mustela gazini, and Mustela jacksoni. Unidentified musteline specimens from the Gray Fossil Site were also included. Results of the character state analysis and DFA proved fairly reliable in distinguishing both extant and fossil taxa. The character state analysis revealed six useful morphological characters to aid in distinguishing between genera while the DFA demonstrated reliable separation of genus, species, and clade. For both analyses, morphology of the carnassials (P4, m1) and M1 contributed most to distinction.