Macau is a rapidly aging city, with 13.8% of the population aged over 65. Social capital has been identified as a crucial protective factor for negative mental health outcomes, yet its relationship with mental health among older adults in Macau remains unclear. This study thematically analyzed the narratives of 19 in-depth face-to-face interviews of Cantonese-speaking elderly aged 60 or above residing in the Seac Pai Van public housing project, the largest public housing project in Macau. This study aimed to collect information on how social networks and social participation impact their mental well-being that may shed light on the promotion of resident mental health in future public housing developments. Results revealed shallow social capital in the community and a high prevalence of loneliness among senior residents who resided in the studied estate. The study also shed light on the participants' thoughts on death, including suicidal ideation, and how they are shaped by their mental health situation and environment. The findings highlight the need to revisit the current mental health policy in Macau and address the urban and architectural design and social organization in new communities, empowering communities to build a friendly environment.