Background Growing literature recognises the impact of the circumstances in which people grow, live, work and age on the development, severity and chronicity of mental health challenges. These have been termed the ‘Social Determinants of Health’ (SDOH). Consequently, SDOH such as employment status, education, housing, and income, are key areas for intervention. However, within many healthcare contexts, these factors are not routinely recorded. Furthermore, knowledge of how mental health professionals explore and respond to these factors in their clinical practice is lacking. Objective To address the evidence gap of how SDOH are considered within day-to-day mental health care, this research will explore how mental health professionals talk about and act upon SDOH. Methods Purposive and snowball sampling was used to recruit 17 mental health professionals practising in the North-west of England. Semi-structured interviews were completed and analysed using reflexive thematic analysis. Results Five themes were identified in the data. These were: dissonance between high relevance and absent guidance; intersection between personal and professional experiences; importance of the therapeutic relationship, dealing with SDOH, and service values. Conclusions Despite the substantial impact of SDOH on service users, current exploration and responses to SDOH within mental health treatment and care are unstandardized and lacking guidance, being reliant on serendipitous practitioner awareness, motivation and organizational factors. Without formal training, guidance and systematic efforts to capture SDOH impacts, mental health services risk perpetuating inequalities. All professionals must engage in efforts to mitigate health inequities to prevent their adverse effects from persisting.