Healthcare workers (HCWs) were at high risk of experiencing psychological distress during COVID-19 pandemic. The objective of this study was to evaluate the impact on HCWs’ mental health in a Spanish hospital. Cross-sectional study of HCW, active between May and June 2020. A web-based survey assessed probable current mental disorders (major depressive disorder [PHQ-8 ≥ 10], generalized anxiety disorder [GAD-7 ≥ 10], panic attacks, post-traumatic stress disorder [PTSD; PLC-5 ≥ 7], or substance use disorder [CAGE-AID ≥ 2]). The Sheehan Disability Scale (SDS) was used to assess severe impairment and items taken from the modified self‐report version of the Columbia Suicide Severity Rating Scale (C‐SSRS) assessed suicidal thoughts and behaviors. A total of 870 HCWs completed the survey. Most frequent probable mental disorders were major depressive disorder (33.6%), generalized anxiety disorder (25.5%), panic attacks (26.9%), PTSD (27.2%), and substance use disorder (5.0%). Being female, having aged 18–29 years, being an auxiliary nurse, direct exposure to COVID-19-infected patients, and pre-pandemic lifetime mental disorders were positively associated with mental issues. Hospital HCWs presented a high prevalence of symptoms of mental disorders, especially depression, PTSD, panic attacks, and anxiety. Younger individuals and those with lifetime mental disorders have been more vulnerable to experiencing them.