The influence of ChatGPT in introductory programming courses has received increasing attention in recent years. However, most research concentrates on programming courses in developed countries and universities, leaving a gap in understanding the effect of ChatGPT on K-12 students. To contribute to this field, this study examines the impact of ChatGPT-assisted learning on students’ performance, learning experience, and attitudes in an introductory programming course in the Philippines. We conducted a between-subjects experiment involving 40 ninth-grade students divided into Manual and ChatGPT groups. We compared their performance by analyzing their assessment scores. Moreover, we conducted a survey to understand students’ learning experiences and attitudes during the course. Results show that ChatGPT does not significantly affect students’ performance, emphasizing the importance of strategic implementation and the development of students’ AI literacy. Nonetheless, the ChatGPT group demonstrated positive learning experiences and attitudes. This outcome shows the potential of ChatGPT to enhance students’ learning experience.