Most of the water bodies are getting polluted day by day due to the disposal of waste into them. The main contributor to household waste includes used cooking oil. Factories and industries also dump waste oil into nearby rivers and lakes, which pollutes the water. The suitability of using waste cooking oil (WCO) in the bituminous mix as a replacement material is studied. The use of WCO in the bituminous mix without compromising its properties helps its reuse in a sustainable manner. This study aims to determine the optimal dosage of WCO in bituminous concrete. With the aim to determine the optimal dosage of WCO, the material properties of WCO as well as the bitumen needs to be assessed. To determine the optimal bitumen content, Marshall Test is conducted in bituminous mix after determining the properties of its components. The optimal bitumen content for Grade II bituminous concrete is obtained. The Bitumen is further replaced by 0–4% of WCO and Marshall Test was conducted. From the study, it is observed that adding WCO to the bituminous mix won’t jeopardize its stability of the mix under the conditions in Palakkad, Kerala, India. The use of WCO as a replacement material in bituminous concrete helps to reduce the environmental impact by reducing the disposal of WCO. It also reduces the production of virgin bitumen which in turn helps in reducing the cost of construction. Also, from the cost comparison study, it is found that the cost of the project can be reduced considerably, upon using WCO. Thus, the proposed mix is found to be economical and sustainable.