Spot (Leiostomus xanthurus) are a popular commercial and sport fish in the Chesapeake Bay region (USA), but have not been managed with age-based models because of a lack of information on vital rates. This study determined that transversely sectioned otoliths were the most appropriate structure to age spot, and subsequently used those ages to estimate biological parameters and evaluate the potential for growth overfishing. Because spot are short-lived, this study explored estimating population parameters using both whole annulus counts and fractional ages. Although fractional ages may be more realistic, parameters estimated using fractions of a year should be interpreted with caution. Growth of spot was rapid (84% of length attained in the first year), the natural mortality rate was high (59% year^-1), and the total mortality rate (natural + fishing) was very high (80–94% year^-1). Spot maximised cohort biomass early in life (≈1 year) and were relatively impervious to growth overfishing. This study illustrates the difficulty in providing management advice for species that maximise cohort biomass about the same time as their first potential spawning event. This study also documents that high exploitation rates and size selective fishing gear probably affect estimates of population parameters.