The aim of this study was to evaluate the impact of a whole-body cryotherapy (WBCT) on various parameters of the mental state of patients depending on their age, gender, and diagnosed illness. The study included 55 subjects - 43 women and 12 men aged from 20 to 70 years. Based on the diagnosed illness, the patients were divided into two diagnostic groups. The first group consisted of patients with spinal pain syndromes (n = 34). The second group comprised patients with peripheral joint disease (n = 21). All patients underwent 10 WBCT sessions. The subjects completed a survey at two time points: before the first WBCT treatment (T1) and after completing the tenth treatment (T2). The World Health Organization Quality of Life-Bref (WHOQOL-Bref) questionnaire and the Psychological General Well-Being Index (PGWBI) questionnaire were used in the study. After a series of WBCT treatments, the WHOQOL-Bref and PGWBI scores significantly improved (p = .005161, p = .000862, respectively). WBCT proved to be more effective in enhancing the mood and well-being of the patients than in improving their quality of life. WBCT has a significant influence on improving the well-being and mood of patients (in terms of both psychological and somatic aspects) and consequently leads to an improvement in their quality of life. The worse the mental state of the patients is prior to the cryotherapy, the stronger its effect. The observed effectiveness of cryotherapy was the strongest in women, patients with spinal pains and in patients with severe depressive symptoms.