Introduction: The COVID-19 pandemic has changed the immunological status of the population, indicating increased activation. The aim of the study was to compare the degree of inflammatory activation in patients admitted for surgical revascularization in the period before and during the COVID-19 pandemic. Materials and methods: This retrospective analysis included an analysis of inflammatory activation assessed on the basis of whole blood counts in 533 patients (435 (82%) male and 98 (18%) female) with a median age of 66 (61–71) years who underwent surgical revascularization, including 343 and 190 patients operated on in 2018 and 2022, respectively. Results: The compared groups were matched by propensity score matching analysis, obtaining 190 patients in each group. Significantly higher values of preoperative monocyte count (p= 0.015), monocyte-to-lymphocyte ratio (p= 0.004) and systemic inflammatory response index (p= 0.022) were found in the during-COVID subgroup. The perioperative and 12-month mortality rates were comparable, with 1% (n= 4) in 2018 vs. 1% (n= 2) in 2022 (p= 0.911), and 5.6 % (n= 11 patients) vs. 7% (n= 13 patients) (p= 0.413), in the pre-COVID and during-COVID subgroups, respectively. Conclusions: Simple whole blood analysis in patients with complex coronary artery disease performed before and during the COVID-19 pandemic indicates excessive inflammatory activation. However, the immune variation did not interfere with one-year mortality rate after surgical revascularization.