Phenolic resin/ZrW2O8 composites were successfully fabricated and their coefficient of thermal expansion (CTE) as well as mechanical properties was investigated. The CTE of the composites decreases from 46 X 10(-6) to 14 X 10(-6) K-1 when the ZrW2O8 volume fraction increases from 0 to 52 vol %. The CTE of the composites is analyzed by some theoretical models; Schapery's upper bound provides the best estimate of the reduction in CTE. The Barcol hardness of the composites increases with an increase in the ZrW2O8 volume fraction. The bending strength of the composites with 19-25 vol % of ZrW2O8 fillers shows a maximum value of 130 MPa, which is 45% larger than that of phenolic resin without fillers. (c) 2007 Wiley Periodicals, Inc.