Solid particle erosion of glass fibre-epoxy composites with the matrix modified by incorporating either carbon black filler or a rubber material known to enhance toughness has been studied, together with a case where both materials are simultaneously included in the resinous matrix. How the semiductile behaviour of the thermoset matrix is affected by the matrix modification formed the primary objective of this work. The erosion weight loss was studied with respect to the angle of impingement. Eroded surfaces of test samples were examined under SEM to observe fracture features. For a matrix containing carbon, the angle for peak erosion remained at 45° despite variations in filler content. But in the case of a rubber toughened matrix, a shift of this angle to 30° is noticed suggesting a change in the mechanism of material removal. When carbon filler was added to the rubber-toughened matrix, it appeared to influence the erosion behaviour.