Introduction: Secondary glaucoma in patients with intraocular neoplasms can be present at the moment of tumor diagnosis or can develop because of the treatment.The aim of the study was evaluation of the frequency of secondary glaucoma occurrence in adult patients with intraocular tumors, definition of mechanisms of its development, especially in case of postradiation glaucoma.Methods: 3001 patients with intraocular tumors treated in the Department of Ophthalmology in Kraków from 2001 to 2010 were included in the study.Results: Secondary glaucoma was diagnosed in 208 patients with intraocular tumor (6,93%). Secondary glaucoma of the open angle was the most frequent mechanism in case of secondary glaucoma diagnosed simultaneously with intraocular neoplasm. The risk of secondary glaucoma was 13% for tumors localized in anterior segment of uvea and 1,2% for tumors localized in posterior segment of uvea. The frequency of postradiation glaucoma was 11%. The most frequentmechanism of postradiation glaucoma is glaucoma of the closed angle. The higher risk of radiation-induced glaucoma is associated with: application of 125I, high radiation dose on the tumor`s top, the irradiation of large size tumors, the tumor localization in anterior segment of uvea.Conclusion: Secondary glaucoma is a frequent complication of intraocular tumors.