Introduction: There are many differences between hemodialysis (HD) and peritoneal dialysis (PD) treatments, including their impact on the psychological status of the patients. In this study, our aim was to compare the psychological statuses of HD and PD patients during the social isolation period due to the COVID-19 pandemic. Methods: We conducted this cross-sectional study on adult HD and PD patients when the curfew measures were in effect. We used an electronic form composed of 3 sections to collect data. In the first section, we collected data on the demographics and clinical and laboratory parameters of the patients. The second and third sections consisted of the Hospital Anxiety and Depression Scale (HADS) and the Impact of Event Scale-Revised (IES-R) questionnaires, respectively. Results: The HD (n = 116) and PD (n = 130) groups were similar regarding age and sex, and they had similar HADS anxiety scores. HADS depression scores were higher in PD patients (p = 0.052). IES-R scores were significantly higher in PD patients in comparison to HD patients (p = 0.001). Frequencies of abnormal HADS-anxiety (p = 0.035) and severe psychological impact (p = 0.001) were significantly higher in PD patients. Discussion/Conclusion: During the social isolation period due to the COVID-19 pandemic, HD patients had better mood profiles than PD patients. A more stable daily routine, an uninterrupted face-to-face contact with health-care workers, and social support among patients in the in-center dialysis environment might be the cause of the favorable mood status. PD patients might need additional psychological support during those periods.