Abstract: The evaluation of the inflammatory state of Behcet`s Disease and it's quantification is most difficult. The difficulty is due to the recurrent attacks and spontaneous remissions that characterizes the disease. In IBDDAM the patients is evaluated on several weeks or months. Each attack is measured separately and given an index. The obtained indexes are added together and the total is divided by the number of months of the evaluation period. The final result is a mean disease activity index that demonstrates quite well the progression capacity of the disease. The inflammatory indexes upon which IBDDAM is calculated is for now rather empirical. One point is given for: Oral ulcers (2 point if more than 5 ulcers at the same time), genital ulcers (1 point for each ulcer), pseudofolliculitis (2 points if more than 10), erythema nodosum (2 points if more than 5), arthralgia, pure cephalea, superficial phlebitis, pathergy phenomenon. Two points are given for phlebitis (each vessel), epididymitis, monoarthritis: Three points are given for polyarthritis, mild CNS and Intestinal manifestations: Six points are given for large vessel thrombosis, moderate to sever CNS or intestinal lesions. Each inflammatory sign of the eye is given 1 to 4 points. If an attack do not heal in 1 month, the same point is given for each additional month.