Two related objectives are the concern in this article. The first is to suggest a conceptual framework for explaining the association between poverty and Common Mental Disorder (CMD) and the mediating factors. The second is to examine statistically the hypothesized role of poverty and other demographic, socioeconomic, and behavioral risk factors on CMD. Data from the Urban Inequity Study Survey (UIS) that was conducted in Cairo in 2007 are used. About 2000 adult females and 2000 adult males were interviewed. Few percent of the study population have non/minimal depression (15% and 16% among males and females, respectively) One-quarter of males and one-third of females have mild depression, and one-third of each have a moderate level. Females exceed males in mild and moderate depression (64.6% vs. 59.2%). About 20% of the females and one-quarter of the males have severe depression. The level of depression significantly declines with education, marriage, and age. Sad events and other difficult life situations such as divorce, widowhood, or spinsterhood, and difficulty in carrying out daily physical functions are strong risk factors. Neither poverty nor living in poor neighborhoods is a risk factor. Males, contrary to females, are significantly impacted by their work conditions.