Summary Corneal thickness measurements were carried out on patients who had undergone combined phacoemulsification cataract extraction with simultaneous intraocular lens implantation in one eye at least six months prior to the date of measurement. The unoperated eye served as control. Another group of patients who had undergone simultaneous phacoemulsification cataract extraction combined with intraocular lens implantation were followed over a two-month period of time, serial corneal thickness measurement being performed. The results indicate that, in surgery performed by experienced surgeons on carefully selected patients, phacoemulsification cataract extraction using the Kelman technique combined with intraocular lens implantation had no significant effect on corneal endothelial function as reflected in corneal thickness changes.