A critical assessment of stress nonuniformity in hollow cylinder torsional specimens used in the study of soil behaviour under general stress paths is presented. It is shown that acceptable levels of nonuniformity in individual stress components adopted in earlier studies can cause serious and unacceptable nonuniformity in stress ratio across the specimen wall. Stress ratio being the most important variable that controls response of frictional granular materials, concepts of stress nonuniformity are advanced in terms of acceptable stress ratio variation across the specimen wall. Thus the region of general stress space that can be explored for material characterization without introducing serious nonuniformities in stress ratio is delineated together with its interrelationship to specimen geometry.