Osteopetrosis refers to a group of rare hereditary disorders characterized by generalized skeletal densification due to limited bone resorption by osteoclasts. The infantile autosomal recessive form represents the most malignant one with onset early in infancy and life expectancy less than 1-2 years without therapy. Frequently, osteopetrosis is complicated by rickets, a condition called osteopetrorickets. Currently, bone marrow transplantation remains the only treatment option. We present a case of infantile autosomal recessive osteopetrosis complicated by rickets in a 2 and a half-month-old female infant with coexistent congenital cytomegalovirus (CMV) infection, successfully treated by hematopoietic stem cell transplantation (HSCT). Diagnostic procedure and differential diagnosis are discussed along with a short review of the literature. Diagnosis of osteopetrosis requires high clinical suspicion, which is enhanced by radiology and confirmed by bone biopsy and molecular analysis. Our patient has been successfully treated by HSCT and has remained in a good general condition thereafter.