Fundamental motor skills (FMS) affect children's physical, social, and cognitive development. To plan successful interventions when promoting the development of children's FMS, the underlying positive determinants for the acquisition of FMS competence during preschool years need to be identified. The purpose of this systematic review was to identify positive determinants of FMS such as stability, locomotor, and manipulative movements in children between the ages of three and six. Five electronic databases (ERIC, PsycINFO, MEDLINE, SPORTDiscus, and Physical Education Index) were used for the systematic search and in our final analysis there were 29 articles. Four categories of determinants were identified: (1) individual characteristics (gender, ethnicity, age, physical activity, physical fitness, and playfulness), (2) education-related (programmes promoting physical activity and motor skill, attendance of physical education lessons, practice schedules), (3) social environments (parent- and family-related variables, older siblings, and sport club participation), and (4) physical environment (population density, size of preschool area, clothing). Age, gender, physical activity, and preschool-based programmes were positive determinants of FMS in preschool-aged children.