Stress hormones have been hypothesized to contribute to the social patterning of cardiovascular disease but evidence of differences in hormone levels across social groups is scant. To examine the associations of socioeconomic and psychosocial factors with urinary levels of cortisol and catecholamines and determine whether these associations are modified by race/ethnicity. Measures of cortisol, epinephrine, norepinephrine and dopamine were obtained on 12-h overnight urine specimens from 942 White, African American and Hispanic participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Linear regression was used to examine associations of income-wealth index, education, depression, anger, anxiety and chronic stress with the four hormones after adjustment for covariates. Higher income-wealth index was associated with lower levels of urinary cortisol, epinephrine, norepinephrine and dopamine, after adjustment for age, sex, race/ethnicity, medication use, body mass index, smoking, and alcohol use. Education and psychosocial factors were not associated with urinary stress hormone levels in the full sample. However, there was some evidence of effect modification by race: SES factors were more strongly inversely associated with cortisol in African Americans than in other groups and anger was inversely associated with catecholamines in African Americans but not in the other groups. Lower SES as measured by income-wealth index in a multi-ethnic sample is associated with higher levels of urinary cortisol and catecholamines. Heterogeneity in these associations by race/ethnicity warrants further exploration.