Abstract: This study is of relevance because it investigates hybrid, unidirectional, polymer composite materials based on carbon and basalt reinforcing fibers and epoxy resin. This study aimed to examine how the contents of carbon and basalt fibers in unidirectional hybrid materials influence the elastic and strength properties. Four specimens differing in contents of carbon and basalt reinforcing fibers were fabricated. The strength, elastic modulus and ultimate strain of the plates were measured by buckling test. The plate made of carbon fiber-reinforced plastic was found to have the highest strength of 1851 MPa and the highest elastic modulus of 96.2 GPa, while the basalt fiber-reinforced plastic plate had lower strength and elastic modulus, 1576 MPa and 43.1 GPa, respectively. The basalt fiber-reinforced plates are prone to be more deformable (4.1%) than relatively fragile carbon fiber-reinforced plates (1.9%). The mechanical behavior of hybrid composites depend on the carbon filler content and its layer arrangement during shaping and testing. It was noted that the strength and elastic modulus of hybrid composites were higher than those of basalt fiber-reinforced plastic, while the strain-to-fracture was higher than that of carbon fiber-reinforced plastic.