Abstract: The present study aimed to examine effluent quality of the Tertiary Wastewater Treatment Plant at Buraidah City (TWTPB) and to demonstrate its compliance with regulations of the Ministry of Water and Electricity (MWE) for tertiary treated effluent. Wastewater samples were monthly obtained form the influent and effluent in TWTPB and analyzed for Total Suspended Solid (TSS), Electrical conductivity, pH, turbidity, NH4+ concentration, some heavy metals, Na concentration, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and counts of fecal and total coliforms over a period of three consecutive years. The maximum values obtained of TSS, NH4+, BOD and COD in the effluent were 5.85, 0.90, 5.75, 24.4 mg L-1, respectively. Removal efficiency for TSS, BOD and COD exceeded 97% in the effluent indicating a high performance of TWTPB. Counts of fecal and total coliforms in the effluent were always less than 2 cfu 100 mL-1 in the effluent showing a high level of sanitation. Sodicity hazard indexes such as Sodium Adsorption Ratio (SAR) and Exchangeable Sodium Percentage (ESP), revealed that effluent salinity was of low to moderate potential problems when reused for irrigation. Residual Sodium Carbonate (RSC) exhibited a negative value implying that no residual carbonate or bicarbonate to react with Na to exacerbate the sodium hazard in soils was found. The effluent of TWTPB was found consistently to satisfy the stringent standards required by MWE for unrestricted irrigation in respect to all parameters measured in this study. It is, therefore, recommended to reuse TWTPB effluent for unrestricted irrigation, taking into consideration soil properties and leaching requirements.