The stability and multivariate effects of life stress, social support, and anxiety from mid to late pregnancy in a sample of low-income women were examined. The sample of 190 was approximately equally divided among black, Hispanic, and white groups. Scores from the two time periods were highly consistent. The multivariate effects of life stress and social support on anxiety were similar at the two time periods, explaining 30% to 34% of the variance in anxiety, over and above the effects of ethnicity or marital status. The prospective test (Time 1 variables predicting Time 2 anxiety), however, explained only 22% of the variance in anxiety. Significant stress-buffering effects from social support were found for both the Time 1 regression and the prospective test. The combination of high life stress and low partner support was associated with the highest anxiety. The findings confirmed that mid-pregnancy measures of these psychosocial variables were valid indicators of their level over the course of the remainder of the pregnancy, allowing for early assessment and intervention to improve perinatal well-being.