It is reported on individual methods for the estimation of the oxalic acid in body fluids, particularly in the urine. The case in question is a survey of the oxalate estimation methods, which, however, has no pretensions to completeness. The at present most actualestimation methods are brought somewhat more in detail. The data are not sufficient for the laboratorytechnical performance of the individual methods, this would transgress the possibilities of the work. However, the original papers are cited which contain all the necessary details. Some technical difficulties and disturbances in the individual estimation methods are also entered. Despite excellent work of several teams the problems of standardization, of the absolutely reliable reference methoda as well as of an objective consideration of advantages and disadvantages of individual, often subjectively judged methods is not yet solved. Comparing these methods, one gets the impression that several reliable methods of the same value are established. It seems that this estimation method brings the greatest progress which will reliably establish so small quantities of oxalate as they are in the blood or in the liquor. By this also the oxalate clearance and the renal oxalate treatment becomes more exactly establishable than up to now.