Most epidemiological studies agree that economically disadvantaged populations are the groups most vulnerable to mental health problems and report lower quality of life among these populations. However, it appears that access to social support plays a role in protecting against the chronic stress resulting from conditions such as poverty. This study is an attempt to clarify the relative contribution of social support to the quality of life of economically disadvantaged populations in two low-income neighbourhoods of Montreal. A random sample of 417 social assistance recipients were interviewed in the respondents' homes. The Quality of Life scale used was the Satisfaction with Life Domains Scale. The availability of social support components was assessed using the Social Provisions Scale. Social support measures were entered into a multidimensional model that included a number of variables identified as having a relationship to mental health. Among the 17 variables included in a multiple regression analysis, emotional support and support providing reassurance of worth accounted for most of the variance in the QOL predicted by the model. Psychological distress also accounted for a fair amount of variance in QOL and younger people and people experiencing food insecurity showed a lower QOL.