Water, sediment and fish samples were collected from the Dhaleshwari River at Tannery Industrial Estate in Savar, Dhaka (23°46'52.68"N, 90°14'22.58"E). Water and sediment samples were collected from five spots: spot 1, spot 2, spot 3, spot 4 and spot 5. Each spot was half a kilometer apart from one another. The study was conducted during July, 2018 - June, 2019. Sampling was done six times during the study period to cover both wet and dry seasons. Water and sediment samples were collected during both wet and dry seasons but fish samples were collected only during the wet season. Fish species were selected by their feeding habit and availability. Labeo rohita, Wallago attu, and Heteropneustes fossilis as the representative of the three feeding groups such as herbivorous, carnivorous and omnivorous (IUCN Bangladesh 2015) were studied. Three samples of water and sediments were collected from each spot following EPA (1997) guidelines. Three samples of each of the three fish species were collected from a fish retailer of Dhar Fish Market, Rajfulbaria, Savar (23°48'35.84"N, 90°14'59.71"E) who sells freshly caught fish from Tannery Estate area of Dhaleshwari River. Same sized fish samples were collected to avoid sampling error. Collected fish samples were kept in an ice box and transported to the laboratory the same day for identification and dissection then preserved at −20°C in the refrigerator at the Biomedical and Toxicological Research Institute (BTRI), Institute of Food Science and Technology (IFST), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh. Water samples were not required to digest and stored in 100 ml volumetric flask after filtration. Collected sediment and fish samples were sun-dried and homogenized using mortar and pestle. Dried samples were prepared and analyzed according to AOAC guidelines (AOAC 2002). 1 g dry sample was weighed using an electronic balance and placed in a 100 ml beaker to which 10 ml of aqua regia (35% HCl and 70% high purity HNO3, in 3 : 1 ratio) was added. The mixture was then digested at 70°C on a hotplate until the solution became transparent. The resulting solution was filtered through filter paper, poured into a 100 ml volumetric flask and diluted using deionized water to make a total volume of 100 ml. Assessment of five heavy metal contents of the samples was performed with Atomic Absorption Spectrophotometer (Model: Shimadzu AA-7000) utilizing acetylene gas as fuel and air as an oxidizer. Digested samples were aspirated into the fuel-rich air acetylene flame and the metal concentrations were determined from the calibration curves obtained from standard solutions. Each determination was based on the average values of three replicate samples. Prior to Atomic Absorption Spectrophotometer (AAS) analysis, digested samples were homogenized using a sonicator. The absorption wavelengths and below detection level (BDL) for the heavy metals were 193.7 nm and 0.001 ppm for As, 217.0 nm and 0.1 ppm for Pb, 228.8 nm and 0.012 ppm for Cd, 324.7 nm and 0.04 ppm for Cu and 232.0 nm and 0.08 ppm for Cr. World Health Organization’s guideline value (WHO 2006) for water As, Pb, Cd, Cr, and Cu is 0.01, 0.01, 0.003, 0.05 and 2 ppm, respectively. Environmental Protection Agency’s Threshold Effect Level (EPA TEL) (MacDonald et al. 2000) for sediment As, Pb, Cd, Cr, and Cu is 5.9, 35, 0.596, 37.3 and 35.7 ppm, respectively. FAO of the United Nations guideline value (FAO 1983) for fish As, Pb, Cd, Cr, and Cu is 0.1, 0.40, 0.10, 1.0 and 30 ppm, respectively. The data were statistically analyzed using the statistical packages, XLSTAT 2014 (Pearson Edition) by Addinsoft and NCSS 12.0.2 Statistical Software (2018) by NCSS, LLC. The mean and standard error were also calculated. Two samples two-tailed t test were used to assess whether water and sediment samples varied significantly between wet and dry seasons, probabilities less than 0.05 (p < 0.05) were considered statistically significant. Individual heavy metal concentrations of three samples (sample size = 3) of each fish species were put in each column and one-way analysis of variation (ANOVA) was used to assess whether fish samples varied significantly among fish groups of different feeding habits, probabilities less than 0.05 (p < 0.05) were considered statistically significant.