Quantitative expression of particle roundness and projection sphericity requires measurement of the radii of curvature of the corners and edges of grains and maximum surface projection particle intercepts. Procedures for measuring these parameters are usually laborious and extremely time consuming, often forcing workers to resort to visual comparison with silhouette or photographic charts to obtain roundness and sphericity. A method is presented in this paper for measuring roundness and sphericity parameters using a Zeiss electronic particle-size analyzer. This instrument was designed to measure grain size for particle size analysis, but it also adapts quite readily to roundness and sphericity measurements. Measurement is quantitatively precise and rapid enough to permit analysis of statistically significant numbers of grains.