Abstract: Muco-cutaneous lesions are the most important signs in the diagnostic criteria of Behcet’s Disease (BD), but they are not specific and can be seen in other disease too. Mucous Membrane Lesions: 1- Recurrent oral aphthosis is the most frequent lesion of BD (96.1%0.6). It was divided in major, minor, and herpetiforme aphtosis. There are also Punctiform, Miliaria, and giant aphthosis. The shape and the size of aphthae can vary from one attack to another in the same patient. 2- Genital aphthosis was seen in 63.9%1.5 of patients. In females, they are larger than OA. In males, they are on the scrotum and on the penis. 3- Erythema may also be seen on the mucous membrane. Skin Lesions is the second most frequent manifestation of BD. It was seen in 67.4%1.5 of the patients: 1- The pathergy phenomenon, which is a skin hyper reactivity to trauma, was seen frequently in BD. 2: The most important cutaneous lesions of BD are pseudo folliculitis (pustular lesions, or papulo-pustular lesions, or acnei form eruptions). 3- Cutaneous aphthosis. 4- Small nodules. 5- Sweet’s like lesions or Behcet’s Cellulitis. 6: Pyodermagangrenosum like lesions are extremely rare. Subcutaneous Lesions: Erythema Nodosum is seen in 22.8%1.3 of cases.The biopsy of the lesion shows a vasculitis, leucocytoclastic or lymphocytic. Muco-cutaneous symptoms are very rich in BD, although non specific.