Non Hodgkin lymphoma especially lymphobastic lymphoma (B– Cell) having skeletal presentation is a rare entity. Among extranodal sites, skin is most common followed by bone & GI tract. It is difficult to suspect this diagnosis without clinically obvious lymph nodal mass or bone marrow involvement. We are presenting here a case report of 11 year old girl having pain and swelling in right limb just above knee joint in absence of any organomegaly and lymphadenopathy. MRI was suggestive of lytic lesion whereas tissue biopsy revealed it to be acute lymphoblastic lymphoma (B– cell). Hence, primary lymphoma of bone should be kept as one of the differential diagnosis of tumorous lesion of bone even in pediatric patients. Early and accurate diagnosis of this entity is required for better management of this condition due to its high cure rates.