Childhood Atypical Teratoid/Rhabdoid Tumour (AT/RT) of CNS is a rare and new clinical event. We report a rare case of this case to highlight the rarity and importance of successful treatment, using AT/RT protocol, although prognosis is dismal among children younger than 3 years. 2½ years old male child on MRI reveals heterogeneously enhancing lobulated mass on left side of the cerebellum with marked fourth ventricle compression leading to proximal hydrocephalus. The excised tumour on histopathology and tumour marker analysis shows the presence of AT/RT Grade IV of cerebellum with no metastasis. Treatment strategy was chemotherapy and cranial radiation and upon follow-up at the age of 5 years the child was asymptomatic on brain MRI.