The increasing trends of urbanisation and the increasing prevalence of people having depression, anxiety, and stress worldwide are alarming. Urbanisation has exerted pressure on housing provision for urban dwellers, and more high-density housing is built to accommodate the migration of people to urban areas. This study aims to assess the effect of living in urban high-density residential on mental disorders of urban population. To understand the relationship between urban high-density living and mental disorders, a questionnaire survey was distributed to the dwellers of urban high-density residents in Federal Territory of Kuala Lumpur based on the characteristics of density, open spaces, and facilities provision. Responses are analysed using Spearman’s Correlation for the questionnaire. The questionnaire surveys show relatively high symptomatology of depression, anxiety and stress and a strong correlation value with high-density living. These results suggest that most people living in an urban high-density living may risk developing mental disorders. On this basis, mental health’s requisites should be considered when designing high-density housing and can support government policies such as in Sustainable Development Goals (SDG), in Ministry of Health policies, in PLANMalaysia development policies, State Structure Plans, District Local Plans, and others related organisation and research.