Pharmacological treatment of allergic conjunctivitis may be based on the therapeutic use of topical steroids; however, because of the side effects, steroids are not clinically suitable in either prolonged treatment, or pollinosis. Because non-steroidal topical drugs are suitable in prolonged treatment, this single-blind study evaluated the following topical drugs: cromoglycate plus chlorphenamine, cromoglycate plus tetryzolin and imidazolin plus nafazolin, compared with placebo. The results confirm significant clinical efficacy of these drugs on signs and symptoms compared with placebo. Thus, "non-steroidal" topical drugs should be the preferred choice in prolonged forms of pollen-induced (e.g. Parietaria and/or grasses) conjunctivitis.