Tails serve multiple functions in salamanders: energy storage, courtship, antipredator defense, and respiration. Differences in life history strategies between males and females may generate sexual size dimorphism (SSD) in tail length. However, the contribution of tail length to SSD is relatively unstudied. Because the basal member of the desmognathan salamander Phaeognathus hubrichti shows SSD in tail dimensions (females have long, thin tails compared to the shorter, thicker tails of males), we hypothesized that other desmognathans may follow the same pattern. We took standard morphological measurements, aged, and sexed 342 Desmognathus quadramaculatus (the largest species of Desmognathus) and 244 Desmognathus aeneus (one of the smallest species) to determine whether SSD in tail length followed the same pattern as in P. hubrichti. Neither Desmognathus species showed SSD in tail length and the trends were in opposite directions. Males of both species had significantly wider tail diameters than the females. Females had a significantly longer distance between limbs than did males. We also found that all three species differ in resource allocation to different body parts as they mature. This suggests that life history traits, and behavioral and ecological requirements, have a stronger influence on body size than does phylogeny in this group of salamanders.