Information has been gathered from a small number of specimens currently recognised as Pseudantechinus mimulus, 18 of which are registered in museum collections. The distribution of these specimens has been mapped and a more defined area than Alexandria Station proposed as the locality of collection of the holotype. Dental characteristics of P. mimulus, by which it was distinguished from P. macdonnellensis, have been examined and found to be more variable than previously thought. A difference between the two species was found in the morphology of the upper fourth molar. P. mimulus appears to be a seasonal breeder. Birth of the young probably occurs in August and September. The penis of P. mimulus is superficially similar to that of P. macdonnellensis. Both species have an appendage on the penis, but in P. mimulus the appendage may be shorter than that of its congener.