Abstract: Introduction: Ocular lesions of Behcet’s Disease (BD) need aggressive treatment to prevent from severe loss of vision or blindness. Although cytotoxic drugs are thought to be the main therapeutic arsenal, no control study has yet been done to demonstrate their efficacy. This study was designed t evaluate the short-term efficacy of pulse cyclophosphamide in a randomized double blind control study. Materials & Methods: PCP was used as Ig per square meter of body surface in I liter normal saline by intravenous infusion, once monthly for the PCP group. Normal saline was administered alone for the placebo group. Prednisolone was given to both groups as 0.5 mg/kg/daily. After 3 months (3 PCP), the two groups were interchanged. Inclusion Criteria were: 1- Fulfilling the Iran criteria for BD. 2- Existence of active posterior uveitis (PU) and/or retinal vasculitis (RV) . A Disease Activity Index (DAI) was calculated for each patient and for each section of each eye (anterior chamber, uvea, and retina) upon their inflammatory state. Visual acuity (VA) was calculated by the Snellen chart. Results: The mean VA improved from 3.7 to 4.9 (t = 3.309, p<0.002) for the PCP group and from 4.4 to 4.5 (t= 0.317, p= 0.75) for the placebo group. The difference between the two groups was significant (t= 2.402, p<0.02). The mean DAI for AU improved from 1.2 to 0.4 (t = 3.273, p< 0.003) for the PCP group and from 1.2 to 0.7 (t= 1.972, p= 0.057) for the placebo group. However, the difference between the two groups was not significant (t= 0.595, p= 0.55). The mean DAI for PU improved from 2.2 to 1.8 (t= 1.898, p= 0.063) for the PCP the group and from 2.1 to 1.8 (t= 1.27, p= 0.21) for the placebo group. The difference between the two groups was not significant (t= 0.495, p= 0.62). The mean DAI for RV didn’t change (DAI=1.2, t=0.127, p=0.9) for the PCP group while it aggravated from 0.9 to 1.1 (t= 1.27, p= 0.21) for the placebo group. The difference between the two groups was not significant (t=0.507, p=0.61). Conclusion: VA improved in the PCP group but not in the placebo group demonstrating the efficacy of PCP and steroids together, but not steroids alone (statistical significance). The difference was not significant for inflammatory indexes because they may improve with steroids alone for a short time.