Objective. To investigate the peculiarities of the development of postoperative complications after surgical treatment of degenerative diseases of the lumbar spine with transpedicular fixation of the vertebrae and their relationship with changes in preoperative laboratory parameters. Methods. A retrospective analysis of the biochemical examination data of 35 patients with degenerative diseases of the lumbar spine who underwent discectomy with transpedicular fixation was performed. In four groups of patients with postoperative complications: 10 patients — inflammation of the what fabrics around metal structures and 5 patients — instability of the metal structure. The results of the examination of 20 people without specified complications served as a comparison group. Comparison was made with a control group (20 practically healthy people). Results. Patients have a significant increase in serum ALT activity by 42.29 and AST by 63.55 %, by 38.37 % of the level of CS content, by 37.21 % of total glycoproteins compared to those in the control group. In patients with soft tissue inflammation around the serum instrument zone, the content of LDLP was recorded by 29.27 %, by 23.53 % of the UA, by 12.34 % of TP results higher by 32.01 % ALT activity and 83 %, 49 % AST, 54.96 % AlP activity, 31.40 % — AlP/AcP, 60.47 % — concentration of CS, 95.57 % — total glycoproteins than in persons in the control group. In the serum of patients with the development of instability of metal structures, 28.55 % was observed by activity of the ALT, AlP — by 38.47 %, AcP — by 48.84 %, less by 58.35 % of AlP/AcP, the CHOL content of 13 88 %, higher by 25.43 % of the LDLP content than such persons in the control group. Content of the P was lower by 31.51 % and the Ca/P ratio was higher by 38.95 %, the content of CS by 83.72 %, total glycoproteins — by 48.83 %. Conclusions. Comparative analysis of the results of preoperative clinical and laboratory examination of patients with degenerative spinal diseases with transpedicular fixation which is reflected in the deviations of their preoperative laboratory parameters from such persons with uncomplicated course of the postoperative period after similar surgery.