Abstract: Pulse cyclophosphamide (PCP) is the most effective and the least toxic treatment in posterior uveitis (pU) and/or retinal vasculitis (RV) of Behcet's disease (BD). Conventional doses (1 g/m2) may be associated with minor side effects such as hair loss, nausea and vomiting. To find whether lower doses, such as those already employed in Lupus nephritis should be useful, we administered IVLDP (0.5 g/m2/month) plus prednisolone (0.5 mg/kg/day) to 40 BD patients with PU and/or RV. A disease activity index (DAI) based on the inflammatory state of each section of each eye was calculated. Visual acuity (VA) and DAI before and after the treatment were compared by the student paired t test. After mean pulses of 6.7 anterior uveitis improved in 77% of the eyes. The mean DAI decreased from 3 to 0.8 (t = 5.926, P < 0.000001). PU improved in 71 % of the eyes. The mean DAI decreased from 2.2 to 0.9 ( t = 6.563, P < 0.000001). RV improved in 59% of the eyes. The mean DAI decreased from 2.6 to 1.7 (t = 2.323, P < 0.03). The mean VA improved from 3.5 to 4.3 on 10 by the Snellen chart (t = 1.804, P = 0.08). Concerning a total adjusted DAI for each patient, 77.5% of them showed improvement. The mean total adjusted DAI decreased from 40.7 to 28.7 (t = 4.246, P < 0.0002). LDP was better tolerated by the patients. Comparing these results with conventional doses of PCP after the same mean number of pulses shows a comparable efficacy of both treatments. It is important to note that in severe retinal vasculitis PCP with the conventional doses is still the drug of choice but the advantage of LDP is its extremely rare side effects.