The Mediterranean gecko (Hemidactylus turcicus) is an introduced nocturnal lizard that often can be seen on and around buildings in the southern United States and in its native Old World range. However, little is known about the factors that determine its selection of microhabitat, except that it does not actively thermoregulate. For example, geckos may forage near lights due to presence of higher concentrations of flying insects or they may select darker sites near refugia to avoid predators. This study investigates the influence of ambient light level (irradiance) and distance to a refuge on selection of microhabitat. During their normal activity period, 54 geckos were hand captured. Snout–vent length, mass, sex, irradiance, and distance to the nearest refuge (crack, crevice, or hole) were determined for each lizard at the time and place of capture. Juvenile geckos tended to be in areas with higher irradiance and farther from refugia than adults. All adults generally selected sites closer to refugia. Adult male and female geckos did not differ significantly in selection of microsites. Thus, we suggest that adult lizards, especially territorial males, exclude juveniles from sites closer to refugia, which are typically of lower irradiance.