On the basis of an extensive electron microscopic study of human urinary stones, a step by step method of stone analysis by scanning electron microscopy (SEM) morphology was developed. A preliminary blind study of 100 consecutive stones demonstrated that the method requires minimum amounts of training and is highly accurate. With several hours of training, accuracy of the stone analysis by SEM morphology alone exceeded 95%. The data indicate that, with further refinements, SEM stone analysis can be accomplished expeditiously and exceed other methods known for stone analysis with economy and accuracy.