Post transplant (Tx) tumors are one of the important long term complications of renal transplantation. They may arise denovo, may be transmitted from the donor or may be due to recurrence of a prevoius tumor. Long-term immuno­suppressive therapy increases the risk of tumor 100 times and the risk is correlated with the level of immono­suppression. Various potentially oncogenic viruses also play a major role in causing these cancers. Aside from non-invasive Kaposi sarcomas, increased rate of production of benign tumors has not been observed after renal Tx and as to our knowledge no cases of post Tx osteoid osteoma has been reported so far. Osteoid osteoma is a benign bone neoplasm that occurs typically in the long bones, such as the tibia or the fibula and in about 50% of cases, in the diaphyseal or meta-diaphyseal cortex It is a relatively common neoplasm, representing about 12% of all primary bone neoplasms. More than 75% of cases present between 5 and 25 years of age and it is rare over the age of 30. The tumor is more common in men with a male-to-female ratio of 2.3:1. Patients with osteoid osteomas typically have pain in the affected bone site, which worsens at night and responds to anti-inflammatory drugs. Here we will present a 49 year old renal Tx male, who presented with increasing bone pain in right upper arm, eight months after renal Tx. Despite an initial normal right humerus X-ray, a raised subperioteal tumor was diagnosed in the lateral border of the right humerus a few months later. Excisional biopsy was performed and the pathologic report was an osteoid osteoma. The patient’s pain which was resistant to most analgesics, completely disappeared after surgery and he is devoid of any lesions at present, 7 months after excision of the tumor.