Background: Cerebral palsy (CP) is the leading cause of childhood disability and commonly affecting cognitive function. Brain neuroplasticity for recovery after brain injury as the underlying cause of CP can be affected by genetic factor, neurotrophic factor, drugs, and age. Brain derived neurotrophic factor (BDNF) as one of neurotrophic factor plays role in brain plasticity. Studies show that BDNF could affect cognitive function. However, relationship between BDNF and cognitive function in children with CP has never been studied before. Objective: To explore the relationship between BDNF and cognitive function in children with CP. Methods: A cross sectional study were carried from June to November 2014 among children with CP Gross Motor Function Classification System (GMFCS) level I and II, range of age 4-14 years old, and meeting the inclusion criteria. BDNF serum level measured by Enzyme-Linked Immunosorbent Assay (ELISA) and cognitive function examination using Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) or Wechsler Intelligence Scale for Children-III (WISC-III). Full Scale IQ (FSIQ) were then grouped according to mental retardation criteria from World Health Organization (WHO) 1994. Analysis were performed using One Way Anova test. Results: One hundred and fifty children with CP fulfilled the inclusion criteria, mean age is 9.62 (__ampersandsignplusmn;2.96) years old, most of the subjects were male (61.33%). Mean BDNF were 39.505 (__ampersandsignplusmn;12.284) pg/ml, mean IQ were 48.51 (__ampersandsignplusmn;18.33). Most children with CP (66%) have moderate and severe mental retardation. Statistically, BDNF were not correlated with cognitive function in children with CP (p=0.99). Conclusion: There were no relationship between BDNF serum level and cognitive function in children with CP__ampersandsignnbsp;(p=0.99).