According to the Copenhagen criteria for Sjögren's syndrome, the diagnosis of keratoconjunctivitis sicca requires the performance of 3 objective ocular tests of which 2 should give pathological results. The tests presently in use are: Break-up time, Schirmer-1-test and Rose-Bengal score. A list of clinical ophthalmological tests has been established in order to enable various SS-study groups to compare results. The list has 3 groups, each containing tests evaluating mainly one characteristic function of the lacrimal system: Tear production, tear quality and ocular surface condition. The tests of the list have been evaluated in 10 1 degree SS-patients and in 10 incipient SS patients. The diagnostic sensitivity and the accuracy of various combinations of the 3 tests have been evaluated. It is suggested that SS-study groups should select one of the marked (*) tests from each group on the list, and that KCS should be defined present, when 2 of the selected 3 tests show pathologically changed results. (table; see text).