Various studies on the use of diesel as base fluid in oilfields applications have been done and revealed the high toxicity and high disposal cost of diesel. Substituting diesel with environmentally friendly oils which will keep the advantages of OBM was one way of avoiding issues associated with its use. Vegetable oils are known as a potentially environmentally friendly drilling fluid but have not received much attention because of its high instability issues. The main instability issue encounter in vegetable oils is oxidative stability. Antioxidants are the most efficient and cost-effective way to improve oxidative stability of oils. In this study, three muds were formulated for comparison. The first one was formulated using diesel oil (A), the other ones using raw Raphia sese oil (B) and (C) as Raphia sese oil with three antioxidants (Red Onion Skin Extract (ROSE), Propyl Gallate (PG) and Citric Acid (CA)), their mud rheological properties, densities, and pH were evaluated at unaged and aged conditions at 120 °F and 160 °F. From the results the addition of antioxidants improved the pH of the Raphia sese OBM from 8.31 to 10.64; Raphia sese OBM and Raphia sese OBM with antioxidants recorded similar densities 9.3 ppg and 9.2 ppg respectively which were higher than that of diesel OBM even with less addition of weighting material. Due to the possible test temperature, the addition of antioxidants did not improve the rheological properties of the Raphia sese OBM. Overall, the addition of antioxidants did not change much in the performance of the Raphia sese OBM as a drilling fluid this was observed from the rating test as Raphia sese OBM and Raphia sese OBM with antioxidants both scored 8 points. Further work will consider testing the muds at HPHT conditions to aid evaluate the effect of the additives on thermal stability. Again, there should be innovative ways of extracting the Raphia sese pulp oil to ensure consistency and quality.