To compare the efficacy, adverse effects, and patient compliance of latanoprost monotherapy with unfixed combination therapy with 0.5% timolol maleate and 1% dorzolamide in the treatment of chronic primary angle-closure glaucoma (CACG), 36 Japanese patients with CACG following laser iridotomy (LPI) were treated for 12 weeks with instillation of latanoprost alone or with unfixed combination therapy of 0.5% timolol maleate and 1% dorzolamide hydrochloride. After 12 weeks of treatment, latanoprost reduced intraocular pressure (IOP) from 22.2 +/- 2.0 mmHg to 14.8 +/- 1.9 mmHg (33% reduction); timolol maleate and dorzolamide hydrochloride also reduced IOP from 22.5 +/- 2.2 mmHg to 17.1 +/- 2.7 mmHg (24% reduction). Latanoprost monotherapy significantly lowered IOP compared with unfixed combination therapy of 0.5% timolol maleate and 1% dorzolamide hydrochloride. Furthermore, a systemic adverse effect of bradycardia was not observed in the latanoprost monotherapy group. Concerning compliance, no significant difference was observed between the two groups. Thus, latanoprost monotherapy is more effective than unfixed combination therapy with 0.5% timolol maleate and 1% dorzolamide in the treatment of CACG following relief of pupillary block in Japanese patients.