The aim of this cross-sectional study was to find out the role of Magnetic resonance imaging (MRI) in the assessment of time of brain insult in cerebral palsy (CP). The study was conducted in the Department of Radiology & Imaging, Mymensingh Medical College Hospital, Mymensingh and a total number of 35 patients with were enrolled from January 2015 to December 2016. Maximum patients (57.2%) were under five years followed by 34.3% were of 5 to <8 years and 8.7% were of 8 to <12 years of age and mean age was 4.7 years. Majority of the patients were male 28(80%) and female were 7(20%). Among the patients 23(65.7%) came from poor, whereas 11(31.4%) came from middle class and only one (2.9%) from rich socioeconomic group. According to gestational age of the patients, 26(74.3%) were term (≥37weeks) at delivery and rest (25.7%) were preterm (<37 weeks). Delayed cry after birth were present in 32 (80%) patients. Regarding types of cerebral palsy spastic diplegia, spastic quadriplegia, hemiplegia and extrapyramidal were found 3(8.6%), 25(71.4%), 4(11.4%) and 3(8.6%) respectively. Abnormal MRI was reported in 94.2% patients and gave clues to time of insult in 79.9% (excluding the 14.3% miscellaneous findings). The findings were mal-developments (5.7%), periventricular white matter lesions (25.7%), cortical or deep grey matter lesions (48.6%), miscellaneous (14.3%) and normal (5.7%). Brain mal-developments were more seen in term than in preterm born children (5% vs. 0%). Periventricular white matter lesions were seen significantly more in preterm than in term born children (77.8% vs. 3.9%). Cortical or deep grey matter lesions occurred significantly more in term than in preterm born children (60% vs. 20%). Based on the study it can be concluded that Magnetic Resonance Imaging (MRI) can help in the assessment of time of insult to the developing brain in cerebral palsy (CP).