Objective: To investigate the relationship between the level of prostaglandin E2 (PGE2) in tears and the severity of dry eye. Methods: Sixty patients with dry eye were selected and investigated with the Ocular Surface Disease Index (OSDI) questionnaire and ophthalmic examination, including tear film break-up time (BUT), corneal fluorescein staining score (CFLS) and tear secretion test (Schirmer I test). The level of PGE2 in tears was measured by enzyme-linked immunosorbent assay (ELISA). The relationship between the level of PGE2 in tears and related indexes of dry eye clinical symptoms was analyzed. Results: The average level of PGE2 in tears of patients with dry eye was (446.39±139.34) pg/mL. The level of PGE2 in tears of patients with dry eye was positively correlated with the OSDI score (r=0.458, P<0.001). PGE2 levels were not significantly correlated with BUT (r=0.164, P=0.354),Schirmer I score (r=?0.076, P=0.460), and CFLS score (r=0.265, P=0.086). Linear regression analysis showed that the level of PGE2 in tears was positively correlated with OSDI score (95% CI: 7.04–20.18, t=4.01, P<0.001).Conclusion: The level of PGE2 in tears is positively correlated with OSDI score, but has no significant correlation with BUT, the CFLS score and Schirmer I test.