This study aims to determine whether playing puzzles can improve children's cognitive abilities in Group B KB (Playgroup) Aisyiyah Tunas Melati, Losari Sub- District, Ampelgading District, Pemalang. This research is a classroom action research (CAR). This research includes planning, action, observation, and reflection. This study uses two cycles, each cycle consisting of three meetings. The subjects of this study were 20 children in Group B KB Aisyiyah Tunas Melati Losari, consisting of 12 boys and 8 girls. The data were collected using observation and documentation. The data were analyzed using descriptive statistics. The results of the Classroom Action Research at KB Aisyiyah Tunas Melati Losari in the initial study showed that there were five children (25%) who developed as expected (BSH) and 15 children (75%) who were starting to develop (MB). In the first cycle, there were seven children (35%) who were starting to develop (MB), eight children (40%) showed development as expected (BSH), and five children (25%) showed very good development (BSB). In the first cycle, a result of 65% was obtained. The success criterion of this action research is 75%. Based on the data from the first cycle, the research continued to the second cycle. In the second cycle, there were two children (10%) showing some development (MB), 11 children (55%) showed development as expected (BSH), and seven children (35%) showed very good development (BSB). The results of the study in the second cycle obtained 90%. Based on these results, this action research was successful. The researcher can conclude that playing puzzles can improve children's cognitive abilities in Group B KB Aisyiyah Tunas Melati Losari, Ampelgading District, Pemalang Regency.