Background:Diabetes is the fifth leading cause of death in the world, which reduces the patients' quality of life (QOL) and is considered as an important subject especially in medicine and medical community. The present study aimed at investigating the QOL of diabetic patients in Iran through meta-analysis.Methods:The search was conducted using relevant keywords in national and international databases including Iranmedex, SID, Magiran, IranDoc, Medlib, Science Direct, PubMed, Scopus, Cochrane, Embase, Web of Science. Questionnaires WHOQOL, SF-36, SF-20, DQOL, QOL, PedsQL, ADDQOL, D-39, DQOL-BCI, SWED-QUAL, IRDQOL, PHG-2, EQ-5D, and IDQOL-BCI were used to assess the QOL. Heterogeneity of studies was assessed using I2 index. Data were analyzed using STATA version 11.Results:In 96 studies of 17,994 people, the mean score of QOL in diabetic patients was based on the questionnaires WHOQOL [66.55 (95% CI: 45.83, 87.26)], D-39 [129.43 (95%CI: 88.77, 170.10)], SF-36 [65.64 (95% CI: 59.82, 71.46)], SF-20 [46.50 (95% CI: 37.19, 55.81], DQOL [61.19 (95% CI: 35.73, 86.66)], QOL [117.91 (95% CI: -62.97, 298.79)], PedsQL [34.36 (95% CI: -31.49, 100.22)], ADDQOL [41.76 (95% CI: 12.01-71.50)], SWED-QUAL [59.19 (95% CI: 21.15, 97.23)], IRDQOL [105.92 (95% CI: 102.73, 109.10)], PHG-2 [61.00 (95%CI: 59.63, 62.37)], EQ-5D [0.62 (95% CI: 0.61, 0.64)], DQOL-BCI [3.40 (95% CI: 3.31, 3.49)], and IDQOL-BCI [22.63 (95% CI: -2.38, 47.64)].Conclusions:The QOL of diabetic patients was evaluated according to different types of questionnaires and the QOL of diabetic patients was found to be lower than normal population.