IntroductionSolitary Fibrous tumours (SFTs) were first described in 1931 by Klemperer et al. as pleural tumours. Since then, it has been reported in many extra-pleural sites but is found to be exceedingly rare. Most of them are reported to arise from the pleura, and only 30% are of extra-pleural origins. Less than a hundred cases of Primary Retroperitoneal Solitary Fibrous Tumours have been described till now. These are rare soft-tissue sarcomas, with mesenchymal origins. The symptoms of these tumours depend on the location. The diagnosis is done mainly by imaging such as ultrasonography, Computed tomography or Magnetic resonance imaging. The standard of treatment for these tumours is by surgical excision with clear margins. The role of adjuvant chemotherapy is controversial.