The purpose of the study is to assess the quality of biochemical studies using sigmametry. Materials and methods. The retrospective analysis for 5 months of 2017 for 19 routine biochemical analytes was performed. The studies were carried out on closed analytical systems: Cobas c 311 («Roche Diagnostics», Germany) and Ilab 300 plus («Instrumentation Laboratory», USA). The amount of Sigma was calculated by the well-known formula using the minimum requirements for analytical quality in the TEmax (%) format and the worst indicators CV(%) and Bias (%) for the observation period. Results. Depending on the number of Sigma, laboratory analytes can be divided into 4 groups: less than 3 identified during control measurements of sodium; from 3 to 4 when examining glucose, LDL cholesterol, potassium, triglycerides; from 4 to 6 — AST, cholesterol; the number of sigma is more than 6 identified in the determination of total bilirubin, ALT, total protein, albumin, creatinine, urea, alkaline phosphatase, HDL cholesterol, iron, amylase and GGT. Conclusion. Assessment the quality of biochemical studies using sigmametry allowed not only to assess their quality, but also to use one of the planning algorithms for intralaboratory quality control.