The study investigated whether social skills and problem behaviours of preschool children differ according to their cognitive styles. The sample group included 366 six-year-old children who attend preschools in Konya. Form A of the Kansas Reflection-Impulsivity Scale for Preschoolers (KRISP), developed by Wright (1971), was used to determine whether the participants had reflective or impulsive cognitive styles, while Preschool and Kindergarten Behaviour Scales (PKBS), developed by Merrell (2003), were used to evaluate social skills and problem behaviour dimensions. Results found that impulsive children were less efficient than reflective children in regards to their social cooperation and social interaction skills, and they exhibited more problem behaviours like self-centred/explosive behaviours, lack of attention/hyperactivity, antisocialism/aggression and social withdrawal.