1. Dispersal can be condition- and phenotype-dependent and related to individual genetic differences. Few studies have addressed the relative importance of these factors on dispersal. We studied the factors behind philopatry and dispersal in juvenile Siberian flying squirrels, Pteromys volans L. 2. The dispersal distance and the distances explored before abandoning the natal nest were not related to any of the condition-dependent factors studied such as the area of high-quality habitat or the number of conspecifics near the natal area. In addition, the body mass (a phenotypic trait) of individuals was not related to philopatry and dispersal in flying squirrels. 3. Genetic variability, measured by microsatellite heterozygosity, was positively correlated with dispersal. The correlation was mainly driven by one locus related to the distances explored before abandoning the natal nest. 4. We conclude that condition- and phenotype-dependent factors did not have detectable effects on philopatry and dispersal, but individual heterozygosity was related to dispersal in flying squirrels. Our results suggest that genetic variability is important behind the dispersal of the species.