A new species of the genus Monodelphis (M. reigi) has recently been described on the basis of a single specimen from the Sierra de Lema in eastern Venezuela. Diagnostic traits with respect to other Monodelphis species are associated mainly with fur colour and skull morphology. In the description of this new taxon, interspecific morphometric comparisons were performed, but not statistically supported. Here we used multivariate analyses to study the relationship between skull size and shape in Venezuelan Monodelphis species, including M. reigi. Our results revealed that M. reigi and M. adusta have similar skull size and are significantly smaller than the other Monodelphis considered. Size-independent analyses showed that the skull shape of M. reigi differs from those of the remaining taxa. Likewise, M. orinoci diverges with respect to brevicaudata and palliolata, whereas brevicaudata is more similar to adusta than to palliolata. Our results support the recognition of reigi and orinoci as full species and the proposal to raise palliolata to the species level. © 2005 by the Society of Vertebrate Paleontology.