General Background: Fine motor development is an important component of early childhood development, particularly in activities requiring hand, finger, and eye coordination. Specific Background: Children aged 3–4 years at KB Aisyiyah Bustanul Athfal 1 Wonoayu showed limited fine motor performance, especially in grasping, picking up and transferring objects, and hand–eye coordination. Knowledge Gap: Classroom activities and available learning media had not provided sufficient and varied stimulation for these fine motor abilities. Aims: This study aimed to examine the application of loose parts media and its results in developing the fine motor skills of children aged 3–4 years. Results: This Classroom Action Research involved eight children and was conducted through planning, action, observation, and reflection in two cycles. Data were collected through observation, interviews, and documentation. Fine motor achievement increased from 25% in the pre-cycle to 50% in Cycle I and 87% in Cycle II, exceeding the predetermined 75% success criterion. Novelty: The study applied loose parts in a structured integrated medium containing activities such as inserting objects into bottles, arranging shells and stones, threading ribbons, and attaching rubber bands, combined with preparatory activities in Cycle II. Implications: The findings indicate that structured loose parts activities can serve as an alternative learning medium for stimulating fine motor development among children aged 3–4 years. Key Findings Highlights Achievement increased progressively from 25% at baseline to 50% after the first cycle and 87% after the second cycle. Seven of eight participants reached the predetermined completion criterion in the second cycle. Preparatory hand activities supported greater readiness, concentration, and coordination during subsequent learning tasks. Keywords : Fine Motor Development, Loose Parts Media, Early Childhood Education, Classroom Action Research, Hand-Eye Coordination