Hospital staff have experienced an increase in psychopathological symptoms such as anxiety or depression during the COVID-19 pandemic. Thus, the aims of the present research were, firstly, to study the effectiveness of the Mindfulness-Based Stress Reduction Program in reducing psychopathological symptoms in hospital staff during the COVID-19 pandemic, as well as, its effectiveness in increasing mindfulness-related skills, self-compassion, body awareness, and reducing stress levels. This parallel randomized controlled trial consisted of 97 hospital workers who were divided into two groups: the experimental group (n = 54) and the control group (n = 44). To test the efficacy of the program, participants' levels of psychopathological symptoms, mindfulness-related skills, self-compassion, body awareness, and stress were assessed and compared before and after the intervention. The results show a significant group x time interaction and significant differences in somatizations (p = .03; rl2p = .047), depression (p = .01; rl2p = .103) and anxiety (p = .02; rl2p = .054). As well as in the following secondary outcomes: from the Five Facet Mindfulness Questionnaire: Observing (p = .001; rl2p = .176), acting with awareness (p = .01; rl2p = .151), nonjudging; (p = .01; rl2p = .103) and nonreactivity (p = .02; rl2p = .101). In the Self-Compassion Scale: self-kindness (p = .029; rl2p = .049), mindfulness (p = .033; rl2p = .047), self-judgment (p = .016; rl2p = .060) and isolation (p = .025; rl2p = .051. And finally, in the Body awareness subscale from SelfBody Connection (p = .044; rl2p = .042). These results highlight the importance of providing hospital staff with skills that help them connect in the present with their feelings and thoughts, without judgment and with selfcompassion, to protect them from suffering an increase in their symptoms of somatization, anxiety, and depression, in adverse times like a pandemic.