Sediment samples were collected from ten selected sites of the lower Meghna River estuary,and six heavy metals were analyzed with Atomic Absorption Spectrophotometry(AAS)to assess the contami-nation level and the metals'association with sediment grain size.The current results revealed that the mean concentrations of the studied metals were ranked in descending order of iron(Fe)(1.29 × 103 mg/kg)＞ zinc(Zn)(42.41 mg/kg)＞ lead(Pb)(12.48 mg/kg)＞ chromium(Cr)(10.59 mg/kg)＞ copper(Cu)(6.22 mg/kg)＞ cadmium(Cd)(0.28 mg/kg).The geo-accumulation,contamination,and pollution load indexes suggested that the lower Meghna river estuary was not contaminated by Fe,Zn,Pb,Cr,and Cu.The mean size of the sediment ranged from 28.92 to 126.2 μm,and the Pearson correlation coefficient showed a significant association between Fe and Pb(coefficient of determination,r2 = 0.836;p ＜ 0.05),and no significant correlation was found between individual metals and grain size,indicating no or low influence on the metals distribution.