Intraocular inflammation (uveoretinitis) is one major complication of Behcet's disease (BD) and responds poorly to drug therapy. This open prospective study was to assess the efficacy of selective granulocytapheresis in patients with refractory uveoretinitis of BD. Fourteen patients aged 20-56 years were treated. Granulocytapheresis was done with an Adacolumn filled with cellulose acetate leucocyte carries or beads that adsorb granulocytes and monocytes from the blood in the column. Each patient received 5 Adacolumn sessions at one session/week over 5 consecutive weeks. The study was designed to allow each patient to serve as his or her own control. The total numbers of ocular attacks (OA) were monitored for 6 months before and after 5 Adacolumn sessions. The number of OA (mean +/- SD) per patient for the 6 months before Adacolumn was 4.21 +/- 1.6 and for the 6 months post Adacolumn was 2.93 +/- 1.39 ( P = 0.0275). Nine patients (64%) improved and 5 did not change or worsened. Further, for a sub-group (n = 7) with duration of BD > or =5 years, the number of OA were 4.71 +/- 1.89 for the first 6 months and 2.29 +/- 1.38 for the second 6 months ( P = 0.0054). The corresponding values for a sub-group (n = 7) with duration of BD<5 years were 3.71 +/- 1.25 and 3.57 +/- 1.13, indicating that patients with long duration of BD are better responders. We conclude that granulocytapheresis might be effective and safe for patients with refractory ocular BD. Further studies are necessary to fully evaluate the clinical efficacy of granulocytapheresis for BD.