The modern scientific direction in the study of the pathogenesis of primary glaucoma is searching for specific biomarkers and regulatory mechanisms of this disease. The aim of the work was to study the level of hydrogen sulfide in eye tissues in animals with adrenaline-induced glaucoma (AIG) and its relationship with intraocular pressure (IOP). The glaucoma model (first group) was induced by injecting 0.1 ml of adrenaline solution into the ear vein for 3 months. In the second group, animals (during AIG simulation) received a hydrogen sulfide donor - daily instillations of 1% NaHS solution into the eye. The third (control) group consisted of intact animals. After 3 months, the level of endogenous hydrogen sulfide was determined in the tissues of the drainage zone of the eye, retina, optic nerve, and intraocular fluid. Glaucoma modeling in rabbits was characterized by a dynamic increase in IOP. A decrease of hydrogen sulfide level in all eye tissues in glaucoma was established. The maximum decrease was observed in the retina by 37.3% when compared with the control. In the second group, the level of endogenous hydrogen sulfide was higher than in the first group in the tissues of the drainage zone by 54%, the retina by 42%, the optic nerve by 37%, and the intraocular fluid by 60%. A decrease and gradual normalization of IOP were found in the second group. The presence of an inverse Spearman correlation between IOP indicators and the level of hydrogen sulfide in all experimental groups was established. We suggest that the established facts confirm the hypothesis regarding the role of a gas transmitter hydrogen sulfide in the pathogenesis of glaucoma.