: Now a day we are facing environment protection problems. Many things which are invented for our luxurious life are responsible for polluting environment due to improper waste management technique. One of them is the polythene (Nylon) bags and sachets which have to be disposed or recycled properly to maintain the beauty of our nature. To address this issue the fibres from used polythene bags and sachets were added in various percentages in the M20 grade concrete. This study thus examines the influence of addition of polythene fibre into concrete at a dosage of 0.1% to 0.75% of total weight of concrete as an additional material in the concrete. The Polythene fibre were cut manually into a rectangular strips of 10mm widths and 50mm lengths which was added to concrete grade 20 mixed in accordance with CNR DT-204/2006, in Euro - code of practice. Tests were carried out as recommended by various recommended codes to determine the properties and suitability of the constituent materials such as aggregates, cement and steel in the mix. From the experiment it was found that at 0.30% inclusion of the polythene fibre, the design strength of the concrete grade 20N/mm2 at 28days was still achievable with a slight decreased in the weight of the concrete cube. More so the flexural or load strength of the concrete at 28 days casting increased marginally from 130N/mm2 (0.00% fibre) to 133.87N/mm2 (0.40% fibre). The flexural strength at this value was observed to increase by about 3.00%. This implies that the optimum fibre content for the flexural strength of the prism was 0.4%. The study also shows that the modulus of elasticity of the concrete prism increased from 21173.32N/mm2 (0.00% fibre) to 21438.14N/mm2(0.40% fibre).This also gives an increase in the modulus of elasticity of about 4.00%. Thus implies that the optimum fibre content for the modulus of elasticity was 0.40%.