Biomonitoring is an effective way to monitor environmental pollution, but its efficiency varies according to the type of organisms, therefore, this study was designed to test the efficiency of using bird feathers and plant Leaves as biomonitors in assessing air pollution with lead, cadmium, chromium, and nickel. Five different areas were selected in Kerbala governorate. Samples were collected from total suspended particulate (TSP) in the air, feathers, and Leaves for comparison and to find the correlation. Heavy elements concentration was measured using atomic absorption spectroscopy. The results showed higher concentrations of heavy elements in TSP, bird feathers, and plant Leaves in urban and industrial areas compared to the reference area, and this was attributed to industrial activities. The overall average concentration of elements was as follows: lead (5.00-67.66 µg g-1), cadmium (0.33-3.66 µg g-1), chromium (0.34-4.39 µg g-1), and nickel (0.34-0.34 µg g-1) in bird feathers and plant Leaves, respectively. Significant differences were found between all areas for each element using plant Leaves, while there were no significant differences using bird feathers except for lead. The Pearson correlation coefficient showed a positive correlation between lead, cadmium, and chromium concentrations in TSP and their concentrations in plant Leaves (P ≤0.01). Based on these results, plant Leaves can be considered a more efficient and effective biological tool than bird feathers in monitoring air pollution with heavy elements due to their ability to trap and accumulate air pollutants.