We retrospectively compared the incidence and level of postoperative intraocular pressure (IOP) spikes in 53 consecutive glaucoma patients undergoing Nd:YAG posterior capsulotomy (YPC) who received apraclonidine immediately postoperatively, with those occurring in 22 consecutive similar patients who did not receive apraclonidine. Postoperative IOP elevations of 5 mm Hg or more occurred in 13% of the apraclonidine recipients and in 59% of the nonrecipients; elevations of 10 mm Hg or more occurred in 4% of the former and in 27% of the latter. Our results suggest that apraclonidine can be a useful adjunct in preventing IOP elevations following YPC in glaucoma patients.