We used a continuous-wave argon laser to produce iridotomies in 28 eyes of 17 patients (12 women and five men ranging in age from 44 to 84 years) with angle-closure glaucoma. We photographed the central corneal endothelium with a contact specular microscope before and after the laser iridotomy was produced. The mean number of cells before treatment was 2,516 cells/mm2 and the mean number after treatment was 2,391 cells/mm2. The mean decrease, therefore, was 125 cells/mm2. This decrease was not statistically significant (P = .09). Retrogression analysis failed to show a correlation between the amount of energy necessary to produce the iridotomy and a decrease in endothelial cell density. Retrogression analysis also failed to show a correlation between the change in endothelial cell density and the time between the laser iridotomy and the performance of postoperative specular microscopy (one to 41 weeks).