Background: The aim of the study was to assess the effect of whole-body cryotherapy (WBC) with subsequent exercise training (WBC group) or exercise-only training (ET group) on endothelium inflammation parameters in patients with ankylosing spondylitis (AS). Methods: The WBC procedure lasted 3 min, and exercise training consisted of one 60 min session a day, which was the same in each group. The ET group was compared to the WBC group. Endothelium (high-sensitivity C-reactive protein (hsCRP), soluble P-Selectin, soluble vascular cell adhesion molecule-1 (sVCAM-1), neopterin), and oxidative stress (lipid hydroperoxide (LHP), protein sulfhydryl (PSH), lipofuscin, paraoxonase-1(PON-1), and albumin) parameters were estimated 1 day before and 1 day after the completion of the study. Results: A significant decrease in hsCRP, sP-Selectin, sVCAM-1, and neopterin concentrations was observed in the WBC group after the treatment. After the treatment, in both groups, LHP and lipofuscin levels and PON-1 activity decreased significantly. The observed drop in these parameters was higher in the WBC group compared to the ET group. Albumin concentration increased in the WBC group after treatment. Conclusion: Procedures of WBC have a beneficial effect on endothelium parameters in AS patients; therefore, this method can be applied in the treatment of this group of patients.