A pilonidal sinus is a cavity in the subcutaneous tissue which is lined by granulation tissue, generally contains hair and communicates with the surface by a track which is usually lined by squamous epithelium continuous with epidermis. The etiological theories of pilonidal sinus are:Congenital Theory: Sequestration dermoid cyst getting infected and ruptured leading to a sinus. This is no longer accepted since it does not date since birth is not preceded by a cyst and is not lined by epithelium.Acquired Theory The most accepted is an inclusion of loose hair under the skin due to continuous friction and negative pressure of area may suck other hairs into the sinus. Pilonidal sinus occurs in young male more than female and in hirsute people than blond ones. This condition increased during Second World War in many individuals who travel by jeep leading some writers to refer to pilonidal sinus as “jeep disease”. The main pathological features is primary track lined by granulation tissue and hairs inside it secondary track were found in about 50% of cases and on pressure on this area may cause escape of pus of seropurulent exudates to come out of the opening. Diagnosis of pilonidal sinus is reached by proper history and clinical examination. There are many surgical approaches for the treatment of pilonidal sinus; excision and healing by open granulation, marsupilization, excision and primary closure or the creation of the flap which was divided into three subgroups; Z-plasty, transposition rhomboid flap and Karydakis flap. All the patients must be followed up and must shave any hair in this area by using depilatory cream to prevent further drilling of the skin by hair.