Introduction: To evaluate the safety and intraocular pressure (IOP)-lowering effects of a ripasudil 0.4% ophthalmic solution in Japanese patients with glaucoma and ocular hypertension (OH) as a post-marketing surveillance., Methods: This was a 2-year prospective observational study in patients with glaucoma or OH who had not previously received ripasudil. Patients registered in the study using a central internet-based system from June 1, 2015 to April 30, 2017. Data on adverse drug reactions (ADRs) and IOP were collected and analysed from the first 3 months of ripasudil treatment., Results: Of the 3058 patients in the safety analysis set, 3016 had IOP data and were included in the efficacy analysis. ADRs were seen in 244 (8.0%) of the 3058 patients. IOP decreased significantly in patients with primary open-angle glaucoma (- 2.9 ± 4.2 mmHg; p < 0.001), normal tension glaucoma (- 1.7 ± 2.4 mmHg; p < 0.001), primary angle-closure glaucoma (- 3.9 ± 5.3 mmHg; p < 0.001), and OH (- 3.8 ± 5.8 mmHg; p < 0.001). Significant IOP reduction was also noted in exfoliation glaucoma (- 3.0 ± 5.5 mmHg; p < 0.001), uveitis-associated glaucoma (- 4.7 ± 7.2 mmHg; p < 0.001) and steroid glaucoma (- 5.5 ± 6.0 mmHg; p < 0.001), but not for neovascular glaucoma (- 2.8 ± 12.1 mmHg; p = 0.669)., Conclusion: Ripasudil was safe and effective in the treatment of glaucoma and OH in Japanese patients, with a low incidence of ADRs or treatment discontinuation, and reduced IOP after 3 months of treatment., Funding: Kowa Company, Ltd., Tokyo, Japan.