Pilonidal sinus disease is usually occurs in the intergluteal region. Many surgical techniques have been described for treatment of this disease. A main surgical complication after operation is infection, while haematoma, on the other hand, is a rare complication. Factor VII deficiency is an uncommon bleeding disorder with an estimated incidence of 1/500.000. We report a case with giant haematoma 2 years after pilonidal sinus operation with out any trauma. Heterozigot Factor VII deficiency is diagnosed with laboratory tests. The patient was discussed in the view of the literature knowledge. ©2007, Firat University, Medical Faculty