This study aims to explore the influences of the CS-unplugged activities in developing problem solving skills of preschool children. The participants were 11 children (4-5 aged) enrolled in a public preschool and Code.org activities were used as an instructional package. Activity evaluation form and interviews were used to understand children's problem solving processes. In order to determine the problem solving performances, the tasks were divided into the meaningful sub-tasks with regard to problem steps of Nance' problem solving model. The results indicated that CS-unplugged activities positively influenced students' understanding and planning performances more than doing and evaluation skills. Preschool children developmental characteristics and the nature of the problems somewhat hampered the development of their performances in doing and evaluation steps. It is hoped that the study may provide insights for the efforts on enhancing preschool children's problem solving processes.