To investigate bleb morphologic features and postoperative outcomes after Ex-PRESS drainage device (Alcon Laboratories) implantation versus trabeculectomy. Retrospective, consecutive case-control series. Information was collected from the charts of 35 consecutive Ex-PRESS procedures and 35 consecutive trabeculectomy procedures with at least 2 years of follow-up. Intraocular pressure (IOP), bleb morphologic features, reduction of dependence on medication, visual recovery, number of postoperative visits, and postoperative complication rates were compared between groups. Average follow-up was 28 months (standard deviation, 3.23 months). Mean IOP measurements were similar after 6 months, then became slightly higher in the Ex-PRESS group at 1 year and at the final follow-up (P = .004 and P = .008, respectively). Final percent IOP lowering was similar between groups (P = .209). Unqualified success was achieved in 77.14% of Ex-PRESS and 74.29% of trabeculectomy procedures at last follow-up (P = 1.00). An additional 5.71% and 8.57% reached qualified success for Ex-PRESS and trabeculectomy surgeries, respectively (P = .99). Evaluation by the Moorfields Bleb Grading System revealed less vascularity and height but more diffuse area associated with the Ex-PRESS blebs, although these differences were absent at study completion. There were fewer cases of early postoperative hypotony and hyphema and quicker visual recovery in the Ex-PRESS group. The Ex-PRESS group required fewer postoperative visits compared with the trabeculectomy group (P < .000). Success of Ex-PRESS surgery, as defined in our study, was similar to trabeculectomy. Final IOP measurements were slightly lower after trabeculectomy compared with Ex-PRESS. Differences in some postoperative outcomes faded with follow-up. There remains a need for long-term prospective studies comparing these 2 procedures. Copyright © 2011 Elsevier Inc. All rights reserved.