Changes in the health care environment, together with specific work-related stressors and the consequences on workers’ health and performance, have led to the implementation of prevention strategies. Among the different approaches, those which are mindfulness-based have been institutionally recommended with an indication provided as to their effectiveness in the management of stress. The aim of the present study was to analyze the efficacy of the mindfulness-based IARA Model® (an Italian acronym translatable into meeting, compliance, responsibility, autonomy) in order to ameliorate perceived stress, anxiety and enhance emotional regulation among health care professionals (HCPs; i.e., doctors, nurses, and healthcare assistants). Four hundred and ninety-seven HCPs, 215 (57.2%) of which were women, were randomly assigned to a mindfulness-based training or control group and agreed to complete questionnaires on emotion regulation difficulties (DERS), anxiety, and perceived stress. Results showed that HCPs who attended the IARA training, compared to the control group, had better emotional regulation, anxiety and stress indices after 6 months from the end of the intervention. Furthermore, the results confirmed the positive relationship between emotional regulation, perceived stress and anxiety. The present study contributes to literature by extending the effectiveness of IARA in improving emotional regulation and well-being in non-clinical samples. Moreover, the study provides support for the idea that some specific emotional regulation processes can be implicated in perceived stress and anxiety. From the application point of view, companies should invest more in stress management intervention, monitoring and training, in order to develop worker skills, emotional self-awareness, and relational resources.