Two thermoplastic matrices, polyetheretherketone (PEEK) and polyetherimide (PEI), are examined in this work in terms of their suitability as carbon precursors for C/C‐SiC composites. The carbon fibers are pretreated between 400 and 1600 °C in nitrogen atmosphere to modify the surface functionality, which was characterized with XPS. An analysis of the C/C‐SiC composition shows an increasing SiC content as a function of the increased fiber pretreatment temperature and the polymer precursor. Bending tests of C/C‐SiC composites exhibit enhanced fiber‐pull‐out effects at a fiber pretreatment temperatures from 400 to 800 °C.