The interlaminar shear strength (ILSS) of a composite containing glass rovings in a polycarbonate-toughened epoxy matrix was determined. The variation of ILSS with glass rovings and polycarbonate content was studied. For a given content of polycarbonate in the matrix, the ILSS increased with volume fraction of the glass rovings. For a given rovings content, the ILSS decreased with increasing polycarbonate content. However, the ILSS of the composites with epoxy alone as the matrix is found to be higher than that of the epoxy/ polycarbonate blend and this was attributed to better bonding between epoxy and reinforcement than that between epoxy/polycarbonate blend and reinforcement. This was further confirmed by scanning electron micrographs of ILSS fractured samples. (C) 2003 Wiley Periodicals, Inc.