Background Coronavirus disease 2019 (COVID-19) has affected more than 5 million people around the world and killed more than 300,000 people; thus, it has become a global public health emergency. Our objective was to investigate the mental health of hospitalized patients diagnosed with COVID-19. Methods The PTSD checklist for DSM-5 (PCL-5), Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder Scale (GAD-7), Trauma Exposure Scale, abbreviated version of the Connor-Davidson Resilience Scale (CD-RISC-10), Perceived Social Support Scale (PSSS) and Demographic Questionnaire were used to examine posttraumatic stress disorder (PTSD), depression, anxiety, trauma exposure, resilience and perceived social support among 898 patients who were hospitalized after being diagnosed with COVID-19 in China. The data were analyzed with t tests, one-way ANOVA and multivariable logistic regression analysis. Results The results showed that the prevalence of PTSD, depression and anxiety was 13.2, 21.0 and 16.4%, respectively. Hospitalized patients who were more impacted by negative news reports, had greater exposure to traumatic experiences, and had lower levels of perceived social support reported higher PTSD, depression and anxiety. Conclusions Effective professional mental health services should be designed to support the psychological wellbeing of hospitalized patients, especially those who have severe disease, are strongly affected by negative news and have high levels of exposure to trauma.