Urban living has rapidly become a highly important due to the increasing rate of mental health problems worldwide. Most people in the urban area live in high-density residential due to limited spaces, land, and higher cost of living. The objectives are to study how urban high-density living environments can affect mental health and the contributing factors to mental health problems. This study was carried out at low-cost flats in Pudu, located in the Federal Territory of Kuala Lumpur. The findings show that urban high-density living environments can become a contributing factor to mental health problems in various ways.