This case study aimed to examine early childhood education (ECE) pre-service teachers' perception on the factors affecting integration of educational computer games to their instruction in two areas: selecting and redesigning. Twenty-six ECE pre-service teachers participated in the study. The data was collected through open-ended questionnaires, interviews, the ECE pre-service teachers' lesson plans, and information about educational computer games they selected and redesigned. Open coding analysis was conducted to analyze open-ended questionnaires and interviews. Moreover, the ECE pre-service teachers' lesson plans and information about educational computer games selected and redesigned were analyzed through the defined categories by experts. The results of the study showed that there were differences between the ECE pre-service teachers' educational computer game integration decisions when they selected and redesigned the games. The ECE pre-service teachers stated that the reasons for these changes were the effects of course activities and game characteristics.