Monitoring lotic ecosystems is vital for addressing sustainability issues. The Al-Shamiyah River is the primary source of water for various daily activities in the Al-Shamiyah district. This study assessed the pollution levels of the river by measuring the concentration and distribution of heavy metals—specifically chromium, cadmium, manganese, copper, zinc, and lead—in both the river's water and sediments. The concentrations of heavy metals in the water ranged from 0.05 to 1.44µg/ L for copper (Cu), 1.57 to 7.25µg/ L for manganese (Mn), 0 to 1.7µg/ L for cadmium (Cd), 0.02 to 1.33µg/ L for lead (Pb), 0.08 to 2.74µg/ L for zinc (Zn), and 0.44 to 1.84µg/ L for chromium (Cr). In the particulate phase, the concentrations ranged from 1.5 to 35.44μg/ g for copper (Cu), 56.16 to 284.49μg/ g for manganese (Mn), 1.50 to 10.72μg/ g for cadmium (Cd), 0.25 to 7.73μg/ g for lead (Pb), 78.71 to 717.76μg/ g for zinc (Zn), and 37.64 to 410.92μg/ g for chromium (Cr). The concentration of dissolved heavy metals in the water was lower than that in the particulate phase. In the sediments, the exchangeable phase contained the following order of concentrations: Mn > Zn > Cr > Pb > Cu > Cd, while the residual phase showed the following order: Zn > Mn > Cr > Pb > Cu > Cd. The concentration of heavy metals in the exchangeable phase was lower than in the residual phase. This study enhances our understanding of the impact of anthropogenic activities on the river's health. The findings highlighted the importance of protecting the river from the influx of heavy metals due to surrounding activities, in order to ensure its long-term sustainability.