Daily tasks can be challenging for young individuals with motor impairments caused by brain disorders. Neurodevelopmental treatment (NDT) aims to enhance motor function by concentrating on the central nerve and neuromuscular systems. However, research on the effectiveness of NDT for children with spastic diplegia in Indonesia, particularly regarding gross motor skills and daily activities, is limited. This study aimed to investigate the effects of NDT on activities of daily living (ADL) and gross motor skills in children with spastic diplegia. This study utilised a pre-test-post-test experimental design. Twenty children diagnosed with spastic diplegia were recruited via purposive sampling from a specialised paediatric rehabilitation centre. The Modified WeeFIM was used to assess ADL, and the GMFM-88 was utilised to measure gross motor abilities. The NDT intervention was administered over the course of 8 weeks, twice a week. Activities of daily living (p < 0.001, mean improvement of 13.6) and gross motor abilities (all GMFM-88 tests, p < 0.05) showed significant improvements. A substantial favourable association (r = 0.702; p < 0.001) was observed between GMFM-88 and WeeFIM scores, suggesting that improvements in motor skills were associated with better daily functioning. Neurodevelopmental treatment helped children with spastic diplegia with their everyday activities and motor function, supporting its role in promoting independence. This study fills a gap in research by evaluating NDT's impact on daily activities and Indonesian children with cerebral palsy and their motor function, contributing to a deeper understanding of its benefits.