Essential oils are used for multiple purposes in different fields; and recently they became vital in the conservation field. Basil oil, one of many essential oils, is known for its fungicidal activity against fungi, which attacks organic materials, such as wood. Throughout the ages sycamore fig wood, which is native in Egypt, was commonly used in archaeological artifacts; yet due to its hygroscopic properties it is usually infested with microorganisms, especially Aspergillus sp. To sustain wooden cultural heritage, it is necessary to protect it from fungal attack using an environmentally friendly material, which is safe for both the object and conservator. As a preliminary step microbiological studies were carried out on a wooden sycamore mask to identify the microbial infestation. This was followed by an experimental study, which aimed to study the effect of basil oil treatment on sycamore wood samples. Heat ageing process was carried out on naturally aged wood to simulate archaeological samples; and for evaluation and assessment of oil treatment FTIR analysis, color change measurements and pH value were carried out. The obtained results suggest that basil oil plays a role in protecting wood not only from microbial infestation, but also from ageing, and reduces the alkalinity of wood directly after treatment. The ratio between lignin/carbohydrates (hemicellulose, crystallized and amorphous cellulose) was not totally affected in the treated samples after heat ageing when compared to the untreated aged samples. Therefore, it is strongly recommended to introduce basil oil as an effective environmentally friendly material in preventive conservation treatments.