Permanent punctal occlusion was performed by two techniques on 27 patients (73 puncta). Patients were randomly assigned to be treated with either thermal cautery or argon laser for keratitis sicca. Follow-up assessment disclosed that the puncta to which thermal cautery was applied remained closed significantly longer than those to which laser treatment was applied (P < .05, log-rank test). Using time to recanalization of a punctum as the end point, we found a long-term advantage of thermal cautery over argon laser treatment.