We studied aggressive behavior of neonate Common Five-Lined Skinks (Plestiodon fasciatus) in a controlled laboratory study. Two neonates of differing sizes were placed on opposite sides of a divided observation chamber for 48 h. Then the partition was removed, a single retreat was placed in the center of the observation chamber, and the behaviors of the two neonates were recorded for 60 min. Neonate Five-Lined Skinks did not interact unless they were within one body length of each other. During an encounter, one lizard typically displayed aggressive behavior (lunging) while the other lizard displayed submissive behavior (avoidance/fleeing), though in 24% of encounters the two lizards showed no reaction. Dominant lizards won significantly more encounters than subordinate lizards. The subordinate lizards displayed tail wiggling behavior significantly more frequently than dominant lizards, suggesting this behavior may be a visual signal of subordinate status. The larger lizard was dominant in 75% of the trials, and as relative size of the dominant lizard increased, so did its percentage of encounters won. The two lizards spent significantly more time on opposite sides of the observation chamber than on the same side, because the subordinate almost always fled from the dominant, often to the opposite side of the chamber. Nevertheless, the two lizards frequently used the retreat at the same time. These results suggest that, in the field, small neonates usually will be subordinate to (and avoid) larger ones while active on the surface, but will readily share retreat sites with larger neonates.