To evaluate the efficacy of Mipragoside, a ganglioside derivative, in vernal keratoconjunctivitis we performed a controlled randomised clinical trial involving 24 patients (mean age 10 +/- 3.4 years, range 5-20 years). Patients received either Mipragoside 0.5% aqueous ophthalmic gel or placebo four times a day for 2 weeks after a week of treatment with placebo. Ocular signs and symptoms were evaluated and considered for statistical analysis. Results show that Mipragoside significantly reduces all symptoms, being most effective on itching (p = 0.01; p = 0.0001) and hyperaemia (p = 0.01; p = 0.0006) after 1 and 2 weeks respectively when compared with placebo. Physician judgement of drug efficacy at the end of treatment was significantly in favour of Mipragoside (p = 0.0001) compared with placebo. We conclude that Mipragoside topical treatment improves symptoms of patients with vernal keratoconjunctivitis and we postulate a possible anti-inflammatory activity of this compound.