The dimensions of women's autonomy and their relationship to maternal health care utilization were investigated in a probability sample of 300 women in Varanasi, India. We examined the determinants of women's autonomy in three areas: control over finances, decision-making power, and freedom of movement. After we control for age, education, household structure, and other factors, women with closer ties to natal kin were more likely to have greater autonomy in each of these three areas. Further analyses demonstrated that women with greater freedom of movement obtained higher levels of antenatal care and were more likely to use safe delivery care. The influence of women's autonomy on the use of health care appears to be as important as other known determinants such as education.