Kaposi sarcoma is a malignant vascular neoplasm uncommonly seen in immunosuppressed patients. Herein we report an unusual case of tonsillar Kaposi sarcoma in a patient with membranous glomerulonephritis treated with prednisolone and cyclosporine. The patient presented after 10 months of starting the treatment with a tonsillar mass. Histological examination was typical of monomorphic spindle cell proliferation with slit-like vascular channels. The tumor cells expressed CD34, D2-40 and positive nuclear stain for HHV-8. Kaposi sarcoma is associated with immunosuppression and rarely occurs in the tonsil. Clinicians should be aware of this rare presentation of Kaposi sarcoma.