​The behaviour of particulate materials is directly affected by their fabric, the imposed state of stress and the inherent characteristics of particles, for example mineralogy, size, material strength and stiffness, angularity and surface characteristics. In general, the characteristics of individual particles have limited effect on the large-strain macrobehaviour of soils. However, experimental results obtained by the authors and other researchers show that the properties of particles do affect smallstrain parameters. The purpose of this note is to review the effect of surface characteristics on soil phenomena, and to report experimental results on the role of surface roughness on wave propagation parameters.