Background: Despite the recent emphasis on technology and engineering in early childhood education, the importance of teaching relevant concepts in early education has been underappreciated in South Korea. This study examined the feasibility and efficacy of a science, technology, engineering, art, and mathematics (STEAM) program integrated into the national curriculum in a Korean early childhood education setting. Children aged 5-6 years (231 girls and 219 boys; treatment group: 334 children; control group: 116 children) were tested on computational thinking, vocabulary, numeracy, self-regulation, and social behavior before and after receiving STEAM curriculum that included robotics activities or an equivalent curriculum. Results: Findings revealed that among the outcome measures, young children in the treatment group exhibited significant increases in computational thinking and expressive vocabulary. Moreover, gender demonstrated a significant interaction effect with the increase in computational thinking as measured by an assessment developed for a specific robotic material as well as in self-regulation and social behavior. Conclusions: This study provides empirical and comprehensive evidence regarding the effectiveness of an integrated STEAM program with developmentally appropriate robotic kits for young children.