In this study we determined the rate of growth of juvenile Florida stone crabs (Menippe mercenaria Say, 1818) reared in the laboratory. We monitored carapace width and intermolt duration through the first 12 juvenile molts. Because all experimental crabs had been reared from eggs in the laboratory, we knew the exact age and molt dates for each individual. Mean carapace width of 1st stage juveniles was 2.0 ± 0.2 mm. Juveniles reached the 13th juvenile stage (15.9 ± 2.1 mm) in a mean of 297.6 ± 32.7 d. The rate of growth in carapace width fit a linear model and was similar in pattern to that reported for juveniles of other brachyuran species.