The plethodontid salamanders Stereochilus marginatus (Many-lined Salamander) and Pseudotriton montanus (Mud Salamander) have overlapping distributions in the southeastern Atlantic Coastal Plain, where they often co-occur in low, swampy habitats. The main objective of this study was to document life-history traits of S. marginatus at Cool Springs in eastern North Carolina, and compare these findings with life-history parameters of a population surveyed in the late 1960s at a nearby locality (Croatan Forest). A second objective was to compare larval development of S. marginatus and P. montanus at Cool Springs. I found that S. marginatus has a larval period of 13–14 months, hatching in early spring and undergoing metamorphosis late in the second spring. Males may breed initially as early as the autumn following metamorphosis, at 19–21 months of age; females probably require an additional year to attain maturity, ovipositing initially at 3 years. Clutch sizes, based on counts of yolked ovarian follicles of dissected females, ranged from 42 to 60. Compared to S. marginatus, the larval period of P. montanus is slightly longer (14–17 months), extending from hatching in winter to metamorphosis in the second spring. Although larval body sizes of S. marginatus and P. montanus overlap considerably, larvae of the latter species tend to grow larger and metamorphose at slightly larger sizes. The phenologies of the life cycles of both species corroborate earlier studies, both across years and across southeastern localities. However, growth and developmental rates of S. marginatus at Cool Springs appear to be accelerated relative to those reported previously for the Croatan Forest population.