Socially unacceptable behaviour is a relatively new field of research in child psychology domain. This research looks at difference in parents' perception of socially unacceptable behaviour among preschool boys and girls in Saudi Arabia. Data for this research was collected using self administered questionnaire survey from 211 parents (123 fathers and 89 mothers) of kindergarten children studying in different kindergartens in Saudi Arabia. Findings of this study indicate that there is some noticeable difference between parents' perception of socially unacceptable behaviour among preschool boys and girls in Saudi Arabia.