© Emerald Group Publishing Limited. Purpose: Developing a dual diagnosis service in Cork, Ireland by way of participatory action research (PAR) background: internationally there is a growing consensus regarding the ideal of integrated treatment. In Ireland, recommendations identified the need for multi-disciplinary team integration and client participation being central to service development. Such recommendations collectively fit most appropriately with PAR, the methodological and theoretical framework best suited to achieve the objectives of the inquiry. PAR’s inclusive philosophy creates processes of negotiation, self-reflexivity and exploration of power issues with the lived experience of communities. Key elements of this approach facilitate the development of emancipatory and participatory democracy whilst highlighting identified social issues through research, learning and action. The paper aims to discuss these issues. Design/methodology/approach: Cyclical processes of planning, action, observation and reflection in cycle one have facilitated the introduction of PAR’s methodological framework into the existing public health (Health Service Executive) system of primary care addiction and mental health services. Developing stakeholder relationships in decision making processes has been pivotal in cycle 1 as the process of collective engagement evolves. Stakeholders begin to experience their collective participation in the methods adopted and a collective sense of ownership and commitment to the iterative process begins to take shape. Stakeholders in cycle 1 have participated in multiple data generation methods including: informal interviews, planned discussion and focus groups, multidisciplinary team meetings, testimonials, observations and reflections. Findings: Cycle 1 of this PAR inquiry has engaged stakeholders (service users and their families, practitioners including; academic/practitioners, a consultant psychiatrist, psychologist, mental health nurses, an occupational therapist, psychotherapists, an acupuncturist, an addiction counsellor, an art therapist) in an integrated process of inquiry. PAR methods adopted in this cycle have facilitated particular dual diagnosis service developments and emerging initiatives (previously unidentified). Actions collaboratively planned for and illustrated in this paper include: the implementation of a psychotherapy group and implementing direct access to an acupuncture clinic. Originality/value: Stakeholders collaboratively experience PAR’s methodological and theoretical approach which has facilitated service developments in cycle 1 of the inquiry. This sets the stage for the completion of actions already in motion and for further initiatives to continue to evolve as cycle 2 processes emerge.