Abstract: Introduction: Manifestations of Behcet’s disease (BD) appear one after another during the course of the disease. Some involvements such as mucous lesions seem to appear early, and others such as gastrointestinal (GI) and neurological (CNS) involvement many years later. This study was planned to find out the chronology of different manifestations of BD. Patients & methods: In a retrospective study, files of all BD patients diagnosed since 1989 were reviewed for the time of appearance of different manifestations in the course of their disease. The mean delay for each item, standard deviation (SD), and confidence interval (CI) at 95% were calculated for each item. Results: A total number of 3542 patients were analyzed. Oral aphthosis (OA) was the most common presenting sign (86%, CI:1.1), while skin lesions(19%, CI:1.3), genital aphthosis (GA, 17.5%, CI:1.2), ocular (13%, CI:1.1) and joint involvement (8.5%, CI:0.9) were the other common signs. Later, during the progression of the disease, the mean delay for development of different manifestations was as follow: OA (3.8 yrs, CI:0.4), skin lesions (5.2, CI:0.3), GA (5.3, CI:0.3), epididymitis (5.4, CI:0.9), joint (5.8, CI:0.4), ocular (6, CI:0.4), CNS (6.2, CI:1.2), deep and superficial phlebitis (6.9, CI:1.9), pulmonary (7.4, CI:4.4), GI (7.7, CI:1.8), cardiac (8.6, CI:3.7), and large vessel involvement (9.1, CI:2.6). Conclusion: This study showes different time delay for the appearance of various manifestations of BD. The great variability in the prevalence of different symptoms of BD between different reports may be mainly due to the different follow up time of patients in these studies.