In a paper published in 1974, it was reported that uro-oxalic stones are found more often in subjects with group O than with group A blood types although the proportions of these two blood types are approximately equivalent in the French population. The present work confirms these data, the ratio of group O to group A renal lithiasis being approximately 3 to 1. In a paper published in 1987, uro-oxalic stones were found to occur preferentially on the left side: 84 on the left and 39 on the right. The present work confirms this notion since in 57 cases, stones were bilateral in 2 cases, on the left in 39 and on the right in 16. Extra corporeal shock wave lithotripsy was performed in 40 of the 57 cases and showed that uro-oxalic stones are most resistant to shock-waves than the other types of stones. They are about as hard as calcium oxalate monohydrate stones or harder in certain cases: A mean of 3,865 shock-waves were required in the 40 cases of the uro-oxalic lithiasis treated with the HM3 Dornier device, while the mean number of shock-waves required for all types of stones in general varies from 2,000 to 2,500. In 4 cases, 5,000 or 6,000 high power shock-waves (7,000 in one session and 9,500 in two sessions) had to be used to obtain a satisfactory result. The calcium oxalate part of these stones is almost always composed of calcium oxalate monohydrate.(ABSTRACT TRUNCATED AT 250 WORDS)