This study describes the authors' surgical technique and the results in 68 consecutive patients with tumors of the iris and ciliary body involving the angle removed by block excision and tectonic corneoscleral grafting between 1980 and 1995. There were 41 (60.3%) women and 27 (39.7%) men whose ages ranged from 14 to 85 years (median, 41 years). Follow-up ranged from 0.5 to 15.2 years (median, 6.3 years). Tumors of the iris and ciliary body with chamber angle involvement were removed with a modified block excision consisting of simultaneous en bloc removal of the tumor with adjacent iris and cornea and sclera in full-thickness. The resulting defect of 6 to 20 mm (median, 9.0 mm) diameter is covered with a tectonic corneoscleral graft. Forty-nine tumors (72.1%) were classified as malignant tumors of the iris and ciliary body. Twenty-one (44.7%) of 47 malignant melanomas showed histologic evidence of scleral invasion of more than one third of scleral thickness. Extrascleral extension of the tumor was present in seven (14.9%) patients with malignant melanomas and in four (21.1%) patients with benign tumors of the iris and ciliary body. The 10-year survival probability of patients with malignant melanomas was 91.4%. The main intraoperative complication was vitreous hemorrhage in 24 (35.3%) patients, and the main postoperative complication was complicated cataract, occurring in 22 (32.3%) patients. Two local tumor recurrences (2.9%) were observed. Four eyes (5.8%) had to be enucleated after block excision. Best-corrected postoperative visual acuity was better than 20/60 in 36 (52.9%) patients. The authors' results indicate that block excision with tectonic corneoscleral grafting may be the treatment of choice for progressive circumscribed tumors of the iris and ciliary body involving the anterior chamber angle up to 150 degrees of its circumference.