The production of plastic bottles by the manufacturing industry has increased drastically over the last six decades across the globe. This rapid production has led to the generation of many waste plastic bottles, thus causing environmental pollution. About 180 tonnes of plastics are generated daily in Kampala, the capital city of Uganda, and around 50% is dumped into the Kiteezi landfill. Instead of putting pressure on the landfill, these plastic bottle wastes could be reused in stabilizing soils with poor engineering properties. The current study investigates the engineering properties of clayey soil reinforced with Polyethylene-terephthalate waste plastic bottle strips. In order to achieve the objectives of the study, the geotechnical and engineering properties of the soil reinforced with waste plastic bottle strips at 0.1, 0.2, 0.3 and 0.4% of the dry unit weight of the soil and non-stabilized soil were determined by conducting laboratory tests, such as particle size distribution, Atterberg limits, compaction test and California Bearing Ratio. The results revealed that the California Bearing Ratio of the soil reinforced with Polyethylene-terephthalate waste plastic bottle strips increased with the increase in the percentage of Polyethylene-terephthalate waste plastic bottle strips up to 0.3%. Beyond 0.3%, a drop in California Bearing Ratio was observed. It indicates that 0.3% Polyethylene-terephthalate waste plastic bottle strips is the optimum percentage for stabilizing low plasticity clayey soils.