Suillus mediterraneensis is an ectomycorrhizal mushroom of two-needle pines. The purpose of the present study is to initially determine the morphological characterization of the species and, thereafter, the mycochemical investigation of the hydro-methanolic extract in order to identify the main chemical classes of their composition in terms of secondary metabolites using simple and rapidly recognized methods and techniques. This survey is being carried out in the coastal region of Ghazaouet within the wilaya of Tlemcen. The morphological determination of the mushroom is based on a range of macroscopic features, including the cap (by its shape, size, color, and surface or its cuticle), the hymenophore, the hymenium (tubes: their color, their shape, and the way they are attached), the stipe (thickness and shape), and the flesh. Furthermore, microscopic examination, either fresh or with reagents, especially Melzer's reagent, is needed to determine the shape, ornamentation, and size of the spores. The macro-chemical reaction of the different parts can be useful. This identification allows us to determine the species S. mediterraneensis, the family of Suillaceae, under Pinus halepensis with the presence of granules on the stipe. The results of the mycochemical screening carried out on the extract showed the presence of substances belonging to the classes of active compounds that include flavonoids, tannins, alkaloids, free quinones, reducing compounds, and coumarins. Anthraquinones, terpenoids, and saponins are absent. These preliminary results encourage the characterization of other molecules, and further studies are needed to evaluate their biological activities.