Rationale, Aims, and Objectives: The risk of mental health problems during the coronavirus pandemic is greater for critical care patients, and has led to demand for services to provide effective training in psychological skills to healthcare professionals (HCPs) to enable a timely, service-wide response. A one-day psychological skills training workshop was developed to build critical care HCPs confidence in screening for psychological distress and delivering Cognitive-Behavioural Therapy (CBT) low-intensity psychological interventions. This study aimed to (1) examine whether the training package improved HCPs confidence in assessing and managing symptoms of depression, anxiety, post-traumatic stress disorder and delirium among critical care patients, and (2) explore how HCPs implemented learned skills in practice. Method: A mixed methods design was used. Self-reported pre and post training questionnaires examined participant confidence in delivering psychological assessments and interventions to patients. A paired-sample t-test and Wilcoxon tests examined differences between pre and post scores. Participants were invited to a semi-structured interview one year after attending the training day. Qualitative data were thematically analysed to explore how practitioners implemented learning into clinical practice. Results: Most participants (55 of 58) completed pre and post questionnaires. There was a significant improvement in participants’ confidence to assess and manage symptoms of psychological distress using brief CBT skills. Four participants were interviewed at follow-up and four themes emerged from analysis: ‘facilitating psychologically-informed conversations with patients’; ‘recognising the benefits of using standardised questionnaires’; ‘facilitating implementation with pre-existing skills and experience’; and ‘barriers to implementation’. Conclusion: The training workshop significantly improved confidence in delivering psychological support with a large effect size. This validates and generalises results from previous studies using similar training in cancer care. Integrating pre-existing skills and knowledge whilst acknowledging and managing HCPs anxieties may help to further boost their confidence in using psychological skills while maintaining rapport with patients.