Background: Reference Intervals (RIs) are important tools to differentiate health and diseasernindividuals. Establishment of RIs specific for a given area is highly recommended, since RI varyrnfrom place to place based on genetics, lifestyle, environmental and nutritional factors. Althoughrnfew studies have been conducted in Ethiopia to determine RI for clinical chemistry in the Amhararnregion and Gilgel gibe, they are limited to the specific population and there is no such studyrnconducted in Tigrai. Therefore; this study aimed to determine RIs for selected clinical chemistryrnparameters among apparently healthy adult individuals in Mekelle city, Tigrai, Northern Ethiopia. rnObjective: To determine community-based reference intervals for selected clinical chemistryrnparameters among apparently healthy adult individuals in Mekelle city, Tigrai, Northern Ethiopiarnfrom December 2018 to May 2019.rnMethod: A cross-sectional study was conducted to establish RI for selected clinical chemistry testrnamong apparently healthy adult individuals in Mekelle city, Tigrai, Northern Ethiopia fromrnDecember 2018 to May 2019. A total of 344 apparently healthy Study participants were selectedrnbased on structured questionnaire, physical examinations, parasitological, and urinalysis. SPSSrnversion 23 was used to analyze the data. RI was determined using 2.5rnthrn and 97.5rn percentiles andrnP value < 0.05 was considered as statistically significant.rnResult: A RI was established for ten clinical chemistry tests. Among them, three parameters hadrnno sex difference [total protein (5.9-8.25 g/dl), albumin (4.3-5.5 g/dl) and fasting blood sugarrn(73.7-115mg/dl)]; whereas the other seven had a statistically significant between the sexes:rnalkaline phosphatase (U/L) [49.3-152 and 58.3-178.6], alanine aminotransferase (U/L) [4.2-23.6rnand 5.2-33], aspartate aminotransferase, (U/L) [12.3-34.1 and 15.2-36.74], bilirubin direct (mg/dl)rn[0.0114-0.553 and 0.019-0.606], bilirubin total (mg/dl) [0.075-0.84 and 0.15-1.08], Urea (mg/dl)rn[8.05-22.85 and 8.7-26.075], and creatinine (mg/dl) [0.46-0.96 and 0.42-1.153] for female andrnmale respectively.rnConclusion: There was a significant difference for ALP, ALT, AST, BilD, BilT, Urea andrncreatinine between sexes. This finding is important to improve the health system by providingrnaccurate RI.rnrnth