We compared measurement of lactoferrin concentration by the Lacto Card solid phase ELIA assay with the Lac-toPlate radial immunodiffusion assay in tears of normal patients and those with keratoconjunctivitis sicca. The Lacto Card, a new lactoferrin assay, allows rapid determination of tear lactoferrin concentration in 10–15 min, a notable improvement over the 3 days required of the Lac-toPlate. There was no statistically significant difference between the accuracy of the two assays in normal patients nor in those patients with a diagnosis of keratoconjunctivitis sicca. Both assays showed a significant decrease in tear lactoferrin concentration in patients with severe keratoconjunctivitis sicca when compared to normal patients. The Lacto Card is a rapid and reliable means of measuring tear lactoferrin concentration in a clinical setting.