Coronavirus is able to affect various organs and systems including the immune system. At the same time, the state of the immune system may be initially changed in patients with pre-existing comorbid non-infectious disorders. The aim of our study was to evaluate biochemical and immunological markers of adverse outcomes in the patients with new coronavirus infection with underlying arterial hypertension. The retrospective study included 47 patients with COVID-19 and arterial hypertension, who underwent a study of C-reactive protein (CRP), interleukin-6 (IL-6), assessing the increased values of these markers and the outcomes of the disease. The study group included 23 male and 24 female patients at the median age of 54 (for men), and 57 years old (for women). Upon admittance of the patients with COVID-19 and hypertension to the hospital, a parallel increase in both CRP and IL-6 was registered in these cases. Statistically significant differences were found in the levels of CRP and IL-6 in patients with a favorable versus unfavorable clinical outcomes. The levels of CRP and IL-6 in deceased patients were higher and did not tend to decrease. Thus, the simultaneous increase in CRP and IL-6 in patients with COVID-19 and hypertension is considered an unfavorable prognostic parameter for patients’ survival.