A series of ketanserin analogs were studied for their effects on intraocular pressure (IOP) recovery curve of rabbits infused with hypertonic saline. Eight out of 31 compounds tested showed a marked delay in IOP recovery indicating that they are potential antiglaucoma agents. Five out of eight compounds showed equal suppression of the IOP recovery curves of treated and contralateral eyes indicating that these compounds could be absorbed systemically to affect the IOP of the contralateral eye. There were three compounds (GC 679, GC 646, and GC 526) which showed more suppression of the IOP recovery curve of the treated eye than that of the contralateral eye, indicating that these drugs might act primarily at the local site to lower the IOP. Therefore, these three compounds could produce antiglaucoma actions with little systemic side effects, if any.