INTRODUCTION: Poor psychosocial support and lack of respectful care for women during childbirth are commonplace in health facilities in low- and middle-income countries. While WHO recommends providing supportive care to pregnant women, there is a scarcity of material for building the capacity of maternity staff to provide systematic and inclusive psychosocial support to women in the intrapartum phase, and prevent work stress and burnout in maternity teams. To address this need we adapted WHO's mhGAP for maternity staff to provide psychosocial support in labour room settings in Pakistan. Mental Health Gap Action Programme (mhGAP) is an evidence-based guidance which provides psychosocial support in resource-limited health care settings. This paper aims to describe the adaptation of mhGAP to develop psychosocial support capacity building materials for maternity staff to provide support to maternity patients, and also to staff, in the labour room context. METHODS: Adaptation was conducted within the Human-Centered-Design framework in three phases: inspiration, ideation, and implementation feasibility. In inspiration, a review of national-level maternity service-delivery documents and in-depth interviews of maternity staff were conducted. Ideation involved a multidisciplinary team to develop capacity-building materials by adapting mhGAP. This phase was iterative and included cycles of pretesting, deliberations, and revision of materials. In implementation feasibility, materials were tested via the training of 98 maternity staff and exploring system feasibility via post-training visits to health facilities. RESULTS: Inspiration phase identified gaps in policy directives and implementation and formative study identified limited understanding and skills of staff to assess patients' psychosocial needs and provide appropriate support. Also, it became evident that staff themselves needed psychosocial support. In ideation, team developed capacity-building materials comprising two modules: one dedicated to conceptual understanding, the other to implementing psychosocial support in collaboration with maternity staff. In implementation feasibility, staff found the materials relevant and feasible for the labour room setting. Finally, users and experts endorsed usefulness of the materials. CONCLUSION: Our work in developing psychosocial-support training materials for maternity staff extends the utility of mhGAP to maternity care settings. These materials can be used for capacity-building of maternity staff and their effectiveness can be assessed in diverse maternity care settings.