Infantile Osteopetrosis is a rare autosomal recessive form of clinical syndrome characterized by the failure of osteoclasts to resorb bone. The defect in bone turnover characteristically results in skeletal fragility despite increased bone mass, and it may also cause hematopoietic insufficiency, disturbed tooth eruption, nerve entrapment and growth impairment. Here we report a case with developmental delay, failure to thrive, pallor and features of extramedullary hematopoiesis. Her x ray shows bone in bone appearance, these features are suggestive of osteopetrosis.