Purpose: This study investigated “Social Disengagement and the Psychological Well-being among Ageing Persons (60 years and above) in Mezam Division, Northwest Region of Cameroon. In the past, care for the elderly was the responsibility of the family and the entire community (respect, care and affection traditionally reserved for them). Today, the elderly face social disengagement, coupled with financial insecurity. The majority of them do not benefit from any pension and for those lucky enough to have one, it is too paltry to allow them to live decently. Hence, this study investigated whether social disengagement affects the psychological well-being of ageing persons. Materials and Methods: The concurrent-nested mixed method research design was used in conducting the study whereby both quantitative and qualitative paradigms were used. A sample of 350 ageing persons was chosen for this study using purposive and snowball sampling techniques. Data were analysed following a triangulation approach in methodology, analytical process and statistical packages. Descriptive and inferential statistical techniques were used to analyse the data collected from the field. For descriptive statistics, measures of central tendencies such as the mean, measures of dispersion (standard deviation), frequency tables and percentages were used to answer research questions while the point biserial correlation test was used to compare relationships within the variables under investigation at 0.05 probability level. To verify the hypothesis, linear regression analysis was conducted at a 0.05 level of significance. Findings: From the data analysed, it was revealed that social disengagement significantly influenced the psychological wellbeing of ageing persons and accounted for 11.1% of its variance R2 =.111, F (1,328) = 40.966, p < 0.01. Implications to Theory, Practice and Policy: Based on these findings, some recommendations were made as follows; family members, the entire community, civil organisations and welfare services should get more acquainted to the aging by creating channels of interaction with them, respecting them, providing social support to them as well as caring and showing affection to them.