A significant percentage of disaster survivors experience negative psychological, physical, and social outcomes after a disaster. The current study advances the literature concerning the Deepwater Horizon Oil Spill (the Gulf Oil Spill) while addressing weaknesses of previous research. The current study includes a clinical sample of 1,119 adults receiving mental health services in the coastal counties of Mississippi after the Gulf Oil Spill. The levels of clinical symptoms reported on the Depression Anxiety Stress Scales (DASS-21) and PTSD Checklist (PCL-S) were examined in relation to other domains of functioning potentially affected by the spill (finances, social relationships, and physical health). Participants reported substantial worsening of their functioning across each life domain. Furthermore, chronic problems in living related to the Gulf Oil Spill were significantly associated with higher levels of psychological distress, although the pattern differed somewhat for persons living above and below the poverty line, with lower income individuals reporting a higher level of overall distress. These data support the perspective that the experience of the Gulf Oil Spill is strongly associated with a deleterious effect on mental health symptoms.