Ceramic matrix composites (CMCs), that consist of silicon carbide (SIC) reinforced with continuous Nicalon(TM) or T-300(R)-fibres, are being developed for many high-temperature structural applications. The large potential use of CMCs has prompted an in-depth investigation and characterization of these materials. Electron microscopy and micro-Raman spectroscopy were used to characterize and compare the SIC matrix crystal structure and morphology of composite materials fabricated by two different chemical vapour infiltration (CVI) processes.