Research on the consequences of unwanted pregnancies can offer useful perspectives on the need to improve and expand the range of family planning options available to women in developing countries. This paper investigates the use of maternal and child health services by women who have unwanted or mistimed pregnancies. The results of our analysis indicate that wantedness of births exerts a significant influence on health care use in Thailand, after controlling for other determinants of utilization. Women with unwanted pregnancies are less likely to seek prenatal care or receive tetanus toxide inoculations. Further, women from disadvantaged socioeconomic groups, women with high parity and those with lower educational levels have the highest proportion of unintended pregnancies. The study concludes by making suitable policy recommendations.