The Tigris River is the primary source of water for human consumption in Iraq and is the ultimate sink for wastewater generated by activities. This research was conducted between November 2021 and September 2022 using 15 physio-chemical parameters (pH, air and water temperature, EC, salinity, DO, BOD, TH, Ca+, Mg+, SO4, TDS, TSS,turbidity, and Chloride), two heavy metal parameters (Cr, and Al), and biological pollutants to analyze temporal and spatial variation and the effects of pollutants sources on the water quality of the Tigris River from the north to the south of Baghdad city. The results show that some values of the tested parameters were higher than Iraqi and WHO standards for the water river, which call for attention to be paid to the load of pollutants entering the river to avoid risks and future problems. On the other hand, the results presented indicate that biological pollution has been diagnosed at the three southern stations (Shuhada'a Bridge, Al-Za'afarania, and Jisr Diyala) with all the types of bacteria in the four seasons, which indicates that increasing the fecal contamination in the middle and southern sampling stations is due to increasing the wastewater discharge into the river body.