Introduction: Nurses who are involved in the caring of COVID-19 patients, are at risk of mental distress. The present study was conducted with the purpose of demonstrating the relationship between stress, anxiety, depression and characteristics of nurses who provide care to COVID-19 patients.Methods: This descriptive cross-sectional study was conducted using the census method from May to June, 2020 on 224 clinical nurses who were working in hospitals affiliated with Babol University of Medical Sciences and were involved in caring for COVID-19 patients. The data collection instruments included the Depression, Anxiety and Stress Scale - 21 items (DASS-21) and the individual characteristic questionnaire. Bivariate and multivariate binary logistic regressions were computed to identify the associated factors. Result: The mean and the standard deviation for stress, anxiety and depression scores were 9.47±7.30, 9.29±7.51 and 8.84±7.22 respectively. 17.4% had stress, 54% had anxiety and 43% had a degree of depression. There were significant relationships between the nurses’ stress level and characteristics including age (OR =3.009, 95%CI 1.46–6.16, P=0.003), having children (OR=0.26, 95%CI 0.11-0.63, P=0.003), work experience(OR=4.50, 95% CI 2.17-9.96, P=0.000) and employment status(OR=0.39, 95% CI 0.16-0.95, P=0.04). Moreover, along with these characteristics, job satisfaction (OR =3.03, 95%CI 5.64–1.63, P=0.000), level of physical activities (OR =0.26, 95%CI 0.08–0.82, P=0.02), exercising (OR =2.27, 95%CI 1.31-3.90, P=0.003) and violence in the workplace (OR =0.27, 95%CI 0.12– 0.56, P=0.001) also had significant relationships with the nurses’ anxiety level. Furthermore, the relationships between the nurses’ level of depression and characteristics including age(OR =2.07, 95%CI 1.15 – 3.72, P=0.014), work experience (OR =21.79, 95%CI 1.04 – 3.10, P=0.03), job satisfaction (OR=3.03, 95%CI 1.63–5.64, P=0.000), exercising (OR =1.76, 95%CI 1.02–3.04, P=0.04), having chronic diseases (OR =0.35, 95%CI 0.15–0.81, P=0.014), violence in the workplace (OR =0.39, 95%CI 0.20–0.75, P=0.005) and sleep (OR =1.77, 95%CI 1.00–3.16, P=0.050) were significant.Conclusion: The authorities should consider a number of the individual characteristics of nurses including age, work experience, gender, marital status, having children, job satisfaction, sleep, violence in the workplace and history of chronic disease in their planning and provide psychological support for them.