Reference intervals (RIs) for biochemical and hematological parameters are fundamental tools for clinical diagnosis, management, and therapeutic follow-up. In Morocco, the RIs used by clinical laboratories and physicians are derived from western populations. Also, RIs of biochemical and hematological parameters specific to the various Moroccan areas are lacking. This study aimed to determine RIs for biochemical and hematological parameters in apparently healthy voluntary adults by following the procedures recommended by the IFCC-CLSI guidelines in 2008 and comparing them to those of literature and other countries. A total of 768 healthy adults from 18 to 60 years old were recruited. Complete blood count and biochemical analyses were performed using hematology analyzer Sysmex KX21N® (Sysmex Corporation, Kobe, Japan) and COBAS INTEGRA®400 plus biochemistry analyzer (Roche, Diagnostics GmbH, Germany) at the laboratory of the hospital Mohamed VI of M'diq, Morocco, and went into effect between November 2017 and December 2020. The data analysis was made by the software SPSS 20.0 and RIs have been established by using the 2.5th and 97.5th percentiles. RIs established include: glucose 3.90 - 6.76 mmol/L for males and 4.01 - 6.87 mmol/L for females; alanine aminotransferase 5.60 - 40.07 U/L for males and 5.60 - 38.71 U/L for females; aspartate aminotransferase 5.60 - 40.08 for males and 5.89 - 39.90 U/L for females; creatinine 47.73 - 113.15 μmol/L for males and 44.64 - 102.28 μmol/L for females; urea 2.2 - 7.6 mmol/L for males and 1.90 - 7.5 mmol/L for females; total cholesterol 2.71 - 5.46 mmol/L for males and 2.64 - 5.89 mmol/L for females; triglycerides 0.58 - 2.01 mmol/L for males and 0.55 - 2.08 mmol/L for females; high-density lipoprotein cholesterol 1.40 - 1.50 mmol/L for males and 1.40 - 1.65 mmol/L for females; and uric acid 157.3 - 410.8 μmol/L for males and 146.1 - 388.5 μmol/L for females. Concerning the hematological parameters, a significant difference (p < 0.05) between both genders was noted for the majority of pa rameters. The present study underlines the importance to establish RIs specific to the Moroccan population in each region for a more rational and reliable interpretation of biochemical and hematological testing in order to avoid errors in diagnosis and treatment of patients.