Despite confronting severe climatic risks, many people prefer to remain in climate hazard-prone areas rather than migrate. Environmental non-migration behaviour, however, has gained relatively little research attention in the field of migration processes. This study aims to unveil the determinants motivating voluntary environmental non-migration decisions in coastal Bangladesh, an area highly exposed to flooding and other climate-related hazards (e.g., soil salinization). Applying a systematic random sampling, we selected 556 household respondents for a questionnaire survey from 14 villages of two coastal districts: Khulna and Satkhira. Applying a mixed-method (i.e., both quantitative and qualitative) approach, major empirical results of this study suggest that even though all respondents lived in a similar situation in terms of climatic hazard and exposure, 88% of the respondents reported themselves as voluntary non-migrants. Furthermore, these non-migrants enjoyed higher socioeconomic and sociopsychological advantages and availed more local support from different government and non-government organizations than involuntary non-migrants. Again, mutual assistance, connection with social groups, natural resource access, sense of secured livelihood, stable societal atmosphere, and participation in decision-making in society appeared to build their higher degree of social capital (𝜒 2(4) = 57.80;p < 0.000) compared to involuntary non-migrants. All these features lead to a favourable environment that ultimately drove the respondents to become voluntary non-migrants.