The work deals with the mechanical properties and biological behaviour of composite materials made of polyether ether ketone (PEEK) polymer and carbon fibers (CF) designed for laryngeal biomaterials. Two types of PEEK–based matrix composites containing carbon fibers in the form of cloth (2D) and short fibers (MD) were made. The composite samples were obtained via hot molding of PEEK/CF prepregs. Mechanical durability of the composite samples aging in Ringer’s solution at 37oC was analyzed. The samples were dynamically loaded under bending force up to 106 cycles. The ultrasonic wave propagation method was applied to study changes in the composites. The mechanical changes were analyzed, taking into consideration the anisotropic structure of the composite samples. The layered composite samples were modified with multiwalled carbon nanotubes (CNTs). The changes in mechanical stability of the composite samples were not significant after fatigue testing up to 1·106 cycles. The biological tests were carried out in the presence of hFOB-1.19-line human osteoblasts and HS-5-line human fibroblasts. The level of type I collagen produced from both types of cells was determined by ELISA test. The tests showed differences between the samples with regard to the viability of the cells.