The strength and toughness of a range of phenolic resin based concretes have been evaluated as a function of matrix resin type, content and catalyst ratios. Two resin systems were examined using resin : filler ratios of 4:1, 5:1, 6:1, 7:1 and 8:1 by weight. Catalyst ratios were varied between 4 and 10% by weight of total resin. Through grading mixes were designed using four single sized silica sands of nominal particle sizes 2.4 and 1.2 mm and also 600 and 300 mu m in combination with a microfiller with a maximum particle size of 150 mu m Gap gradings were also produced using two of the sand components (1.2 mm and 300 mu m) and the microfiller. Microfillers employed included silica flour, china clay and spheriglass 5000. Strength ranged from 4.7 to 7.9 MPa measured in axial tension and 21.3 to 31.4 MPa measured in flexure using four point bending. Fracture toughness, evaluated as the critical strain energy release rate, G(1c), was determined using precracked double torsion specimens. Typical values ranged from 0.13 to 0.22 kJm(-2).