Mycelium composites consist of particulate lignocellulosic materials, e.g., sawdust from the timber industry structured as a solid matrix resulting from the mycelial growth. Many protocols have been proposed based on different strains and substrates. However, the influence of intrinsic elements, such as the structure of the hyphal system on the main parameters required by the industry still needs to be researched. The main goal of this work is to assess the performance of five Patagonian lignocellulolytic fungal species for producing mycelium composites. Strains of these species were studied in order to assess the relation between basidiome hyphal structure and the hyphal structure of mycelium-based materials. Comparisons of the hardness in the Janka scale were performed with commercial expanded polystyrene. Composites resulting from the growth of Pleurotus ostreatus, Nothophellinus andinopatagonicus and Funalia trogii successfully formed composites, showing alower quality than Ganoderma australe. Ryvardenia cretacea in turn completely failed to colonize the substrate. The material resulting from the growth of Ganoderma australe on pine sawdust (a substrate chosen based on its local availability) is proposed as a good substitute with improved resistance.