Rho kinase (ROCK1 and ROCK2) is a serine/threonine kinase that serves as an important downstream effector of Rho GTPase, and plays a critical role in regulating the contractile tone of smooth muscle tissues in a calcium-independent manner. Several lines of experimental evidence indicate that modulating ROCK activity within the aqueous humor outflow pathway using selective inhibitors could achieve very significant benefits for the treatment of increased intraocular pressure in patients with glaucoma. The rationale for such an approach stems from experimental data suggesting that both ROCK and Rho GTPase inhibitors can increase aqueous humor drainage through the trabecular meshwork, leading to a decrease in intraocular pressure. In addition to their ocular hypotensive properties, inhibitors of both ROCK and Rho GTPase have been shown to enhance ocular blood flow, retinal ganglion cell survival and axon regeneration. These properties of the ROCK and Rho GTPase inhibitors indicate that targeting the Rho GTPase/ROCK pathway with selective inhibitors represents a novel therapeutic approach aimed at lowering increased intraocular pressure in glaucoma patients.