In this study, biocomposite materials resistant to various effects (heat and humidity) were produced by using olive seed powder and basil leaf powder as reinforcing elements at different ratios (30%-0%, 25%-5%, 20%-10%, 15%-15%, 10%-20%, 5%-25%, 0%-30%) and the effects of these ratios were obtained as a result of tests. In the samples produced using olive kernel powder and basil leaf powder, it was observed that the powder ratio added to the mixture had significant effects on the properties in tensile, impact, hardness, water absorption, and ignition loss tests. In the tensile strength test, the sample produced using 30% olive pomace powder showed the highest tensile strength with 28.892 MPa, while a value of 23.39 MPa was observed with 30% basil leaf powder. In the impact energy test, the BLP5 sample produced using 5% basil leaf powder had the highest resistance with 0.808 J. In the Vickers hardness test, the BLP30 sample with 30% basil leaf powder reached the highest value (150.4 HV) among the samples produced using basil leaf powder, while the BLP0 sample produced using olive pomace powder with the same 30% pomace powder ratio reached 120.11 HV. In the water absorption test, a decrease in water absorption capacity was observed as the basil leaf powder ratio increased and the lowest absorption capacity was observed in BLP30 specimen produced using 30% basil leaf powder. However, it was observed that the specimens produced using olive seed powder by weight had less water absorption capacity than the specimens produced using basil leaf powder by weight. In the ignition loss test, the weight loss increased with higher olive seed or basil leaf powder content, reflecting the greater organic fraction in these samples. Based on these results, it is aimed to be used in the automotive sector in areas where water and heat contact is high.