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.