The participants of the Blood Biochemistry Section were interviewed using a questionnaire within the framework of the Federal System for External Assessment of the Quality of Clinical Laboratory Studies in order to study used procedures for intralaboratory quality control. The questionnaire was filled out by less than 40% of laboratories. The key feature of documents regulating intralaboratory control is the preliminary estimate of the analytical characteristics of the procedure within the framework of the set series. The proportion of the cases that the mean value displacement or the variation coefficient of the set series has not been found to comply with the normative documents is significantly higher in most biochemical parameters at the laboratories making an intralaboratory control using one control material as compared to those who apply two control materials. The share of poor values of control diagrams also increases if the laboratory employs a control animal rather than human blood material and in the cases that the control material has been made by another manufacturer than a kit of used reagents. Analysis these values for individual biochemical parameters has shown that it is necessary to improve analytical procedures for determining the concentration of calcium, sodium, albumin, and chlorides, on the one hand, and for actualizing the normative standards for amylase, creatine kinase, gamma-glutamyltransferase, alkaline phosphatase, cholesterol, and triglycerides on the other hand.