Keratoconjunctivitis sicca (KCS) has not been reported as occurring as a single entity in the acquired immune deficiency syndrome (AIDS) population. In a survey of human immunodeficiency virus type 1 (HIV-1) infected male patients, the authors found that 21% (9/42) had signs and symptoms compatible with KCS with positive Schirmer test results. Tear osmolarity determinations were obtained from this group and from an age- and sex-matched group of HIV-infected patients without symptoms of KCS and with negative Schirmer test results. Eighty-nine percent of the suspect group had increased tear osmolarity, whereas none of the control patients had a hyperosmolar tear film (P less than 0.0001). Results strongly suggest that KCS occurs at a significantly greater rate in male individuals infected with HIV-1 than in the general population.