This study aims to assess the water quality of the Tigris River in Baghdad. A water quality index (WQI) was calculated based on physicochemical parameters and compared to established limitations, followed by statistical testing. From 2009 to 2019, data on 17 physicochemical parameters of river water were collected from upstream and downstream monitoring stations in Baghdad. WQIs at both monitoring stations were found to be poor, with 10 parameters exhibiting statistically significant differences in their concentrations. The WQI for the upstream station (Al-Karkh) and the downstream station (Al-Wahda) showed poor water quality at both locations, with a further decline observed downstream. A normality test was conducted on the dataset of water parameters, revealing that eight parameters followed a normal distribution while four exhibited a non-normal distribution. The t-test and Wilcoxon signed-rank test identified statistically significant differences across all water parameters. The water quality of the Tigris River has deteriorated due to the discharge of pollutants and a lack of effective environmental policies and regulations governing river water.