This research project aims to clarify the factors that impact successful aging in Assisted Living facilities (ALFs) in Denton County, Texas. We hypothesize that social disengagement decreases physical and mental components of quality of life. This exploratory research project employed standardized questionnaires to assess residents in the following domains; HRQOL, social engagement status, level of cognition, depression, and the level of functioning. This study collected data from 75 participants living in five ALFs. The average of Physical Component Scale (PCS) and Mental Component Scale (MCS) was 35.33, and 53.62 respectively. None of the participants had five or more social contacts out of facilities, and two-third of them had two or less social contacts. On average, those participants who were more socially engaged had higher score of MCS compared with disengaged counterparts. The level of physical function significantly affects social engagement, when people with more disabilities are more likely to be socially disengaged. Social engagement and depression significantly impact MCS, when depression is a mediating factor between social engagement and mental component of quality of life. Considering the expansion in aging population in the United States within the next three decades, the demand for high quality long-term care will skyrocket consequently. This study reveals that external social engagement can sustain HRQOL of residents in assisted living facilities.