We examined 70 urinary sediments of 35 children with non-glomerular hematuria (NGH) and 65 urinary sediments of 17 children with glomerular hematuria (GH) by phase-contrast microscopy at 1,000 X magnification. In each urinary sediment 200 erythrocytes were classified into 18 types of "non-glomerular erythrocytes" and 15 types of "glomerular erythrocytes". According to the percentage of greatly altered erythrocytes the urinary finding was termed isomorphic, mixed or dysmorphic. In 91% of the urinary sediments of patients with NGH the erythrocyte pattern was isomorphic, and in 91% of the urinary sediments of children with GH it was dysmorphic. 9 types of non-glomerular erythrocytes and 10 types of glomerular erythrocytes constituted 94.5% of all 26,809 erythrocytes examined. Torocytes (doughnut-like cells) can be considered characteristic for GH. This study demonstrates a high specificity of this method in discriminating NGH from GH. The exact morphological description of urinary erythrocytes allows the method to be reproducible. For future use examiners can concentrate on the 19 commonest erythrocyte types.