Executive function skills constitute an important basis for learning and adaptation in early childhood. The executive function skills can easily improve in children who uses good practices in preschool. These skills are especially important because they help children overcome all complex tasks required to manage themselves. The aim of the present study was to examine abstraction and cognitive flexibility components, which are important components of executive functions, in 4-6-year-old Turkish children and refugee children attending kindergarten and nursery school using Flexible Item Selection Task (FIST). In addition, the research aimed to compare the abstraction and cognitive flexibility according to gender and age variables using three different sections: Turkish students attending kindergarten, Turkish students attending nursery school and refugee children attending nursery school. The study was a survey type of quantitative research, and a cross-sectional survey approach was used. The participants were 99 Turkish and refugee children who were 4-6-year-old and attended kindergarten and nursery schools in central town of a province in Turkey. The schools where 48-60-month-old children are taught are called kindergarten in Turkey while the schools for 61-72-month-olds are called nursery schools. The study included one kindergarten and two nursery schools. These schools are located in the city center, long distances from each other and in different neighborhoods. The Turkish children in the study were both kindergarten and nursery school children whereas refugee children were only nursery school children who attended to the nursery school together with Turkish children. Children were evaluated by their class-gender and class-age combinations. There were 16 Turkish boys and 16 Turkish girls attending kindergarten, 17 Turkish boys and 19 Turkish girls attending nursery school, and 16 refugee boys and 15 refugee girls attending nursery school. In terms of class-age combinations, there were 15 Turkish students in kindergarten, 16 Turkish students in nursery school and 16 refugee students in nursery school in 48-60-month age group while 61-72 months age group had 17 Turkish students in kindergarten, 20 Turkish students in nursery school and 15 refugee students in nursery school. Flexible Item Selection Task (FIST) was used as the data collection tool in the study. The implementation of the measuring tool was carried out individually with each child by the researcher and took about 10 minutes. The results of the study revealed that there was no significant difference among Turkish kindergarten, nursery school and refugee children nursery school groups for abstraction scores based on gender and age groups. However, a significant difference was found between Turkish and refugee children for the cognitive flexibility scores. While the gender and age groups of Turkish and refugee children attending kindergarten had no significant differences for the abstraction component, there was a significant difference between gender and age groups for cognitive flexibility scores. For a more detailed analysis, studies dealing with high-level cognitive skills and working memory, one of the components of executive functions, are needed.