The effect of sodium hyaluronate eye drops in the treatment of severe keratoconjunctivitis sicca (KCS) was evaluated in a double masked crossover trial, comparing the effect of a 0.1% solution, a 0.2% solution and placebo in 20 patients. We found significantly decreased rose bengal staining and increased break-up time following 0.2% treatment compared to placebo. No significant difference was found in the Schirmer values and the cornea sensitivity. The patients significantly preferred sodium hyaluronate treatment. We conclude that sodium hyaluronate eye drops seem to be a valuable new agent in the management of KCS.