Dispersal occurs when an individual leaves its natal area or home range, travels through adjacent areas, and then establishes a new home range where it will attempt to reproduce. Previous studies have suggested that subadults (i.e., hatchlings and juveniles) are the main agents of dispersal among introduced populations of Mediterranean Geckos, Hemidactylus turcicus. We derived a testable hypothesis for subadult dispersal in Mediterranean Geckos. In September 2006, we conducted tethering experiments to test the prediction that adults act aggressively toward subadults. From June to October 2006, we conducted 18 mark-recapture samples to test predictions of perch height occupancy and relative presence of adults and subadults at buildings and areas between buildings (i.e., transient habitats). As predicted, subadults occupied lower regions of buildings than adults, and subadults were disproportionately abundant in transient habitats. Apparently because of small sample size, there was no difference in the relative presence of adults and subadults at recently occupied buildings (i.e., arrival habitats). Our results supported the hypothesis that hatchlings were the main agents of diffusion dispersal within our study population and suggested that hatchling dispersal may be motivated by hostile encounters with adults. It was also clear that Mediterranean Geckos attempt to disperse from buildings more frequently than previously suggested.