<![CDATA[This study aims to enhance the cognitive abilities of children with developmental delays at State Kindergarten 2 (TK Negeri 2) in Rantau Pulung District using the Project-Based Learning (PjBL) model. The issue addressed is the children's low cognitive ability, specifically in shape recognition, shape matching, size differentiation, and completing tasks that require hand-eye coordination. These difficulties stemmed from instruction that was overly teacher-centred and lacked concrete learning experiences; thus, a more active and meaningful learning model—tailored to the characteristics of children with learning delays—was required. The study employed the Kemmis and McTaggart Classroom Action Research (CAR) model and was conducted over two cycles. Each cycle comprised the stages of planning, implementation, action, observation, and reflection. The subjects were three children aged 4–5 years with developmental delays at the aforementioned kindergarten. Data collection involved observation and documentation, and data analysis used descriptive quantitative methods (percentages). The results indicate that implementing the Project-Based Learning (PjBL) model incrementally improved the children's cognitive abilities. The average cognitive ability score rose from 35.00% at the pre-action stage to 51.22% in Cycle I, reaching 82.12% in Cycle II. This improvement was supported by an adapted PjBL approach that used concrete materials, simplified project activities, step-by-step instructions, and teacher guidance during project execution, helping children better grasp shape concepts aligned with their developmental stages. Consequently, the Project-Based Learning (PjBL) model effectively enhances the cognitive abilities of children aged 4–5 years with developmental delays.]]>
