This study was conducted to determine the effect of rice straw on some chemical properties and heavy metals accumulation of fish pond bottom sediment in earthen fish ponds. The present work had been conducted in the world fish center during the period from May to December 2017 in six earthen fish ponds having equal areas (1000 m2) and 1 m water depth All ponds cultured with mono six Nile tilapia fry in the rate of 3 fingerling/ m2.  All ponds were fertilized with dry chicken manure in the rate of 15 kg/pond/week, and divided into two treatments, each of 3 replicates; the first one (T1), act as control, while the second (T2) received 45 kg dry rice straw/pond.  Samples were collected at the beggining and at the end of the experiment; from both treatments as well as from the source of water. The study showed that the sediment pH lied in the alkaline side and negatively correlated with organic matter contents. Concentrations of organic matter and organic carbon were significantly higher in T2 than T1, indicating that rice straw increased total carbon in  the bottom sediment. Total nitrogen and total phosphorus (TP) concentrations were varied significantly among treatments.  The highest value had been recorded in T2. The different investigated parameters were significantly increased at the end of experiment compared to the beggining, expect for C/N and N/P ratios which decreased at the end of the experiment. Concerning the investigated heavy metals; their concentrations had the, following order: Fe > Zn > Cu > Pb > Cd and tended to be higher in the source water then in T1, while the lowest concentrations had been observed in T2. It's observed that the metals concentrations were significantly decreased at the end of experiment compared to the beginning expect for Cd which increased at the end of experiment. The results of this investigation indicated that rice straw improved sediment characteristics, increased nitrogen availability and decreased the investigated heavy metals residues.