The purpose of this prospective study was to examine the causal relationship among daily hassles, social support, self-care deficit and health outcome of pregnant women based on Orems self-care theory. Health outcome of pregnant women were complication of pregnancy and baby birth weight. Subjects were recruited by purposive sampling, consisted of 284 normal primigavidas attending antenatal clinic at Health Promotion Center Region 10, Chiang Mai. Instruments used in the study were Daily Hassles Scale modified from the tool developed by DeLongis et al. and the Support Behavior Inventory developed by Brown. Instruments using for appraising of self-care deficit and complication of pregnancy and baby birth weight were developed by the investigator. The hypothesis model and the reduced model were tested by using multiple regression analysis with enter method. The goodness of fit of reduced model and empirical data were tested by Specht technique. The results of the path model showed that: Daily hassles had positive direct effect on self-care. with statistical significance at the level of .OO1. Daily hassles had a positive indirect effect on complication of pregnancy through self-care deficit and had a negative indirect effect on baby birthweight through self-care deficit and complication of pregnancy. Social support had a negative direct effect on self-care deficit with statistical significance at the level of .O1. Social support had a negative indirect effect on complication of pregnancy through self-care deficit and had a positive indirect effect on baby birthweight through self-care deficit and complication of pregnancy. Self-care deficit had a positive direct effect on complication of pregnancy with statistical significance at the level of .01 and had a positive direct and indirect effect on baby birthweight through complication of pregnancy with statistical significance at the level of .O1. Daily hassles and social support had statistical significance in the prediction of self-care deficit (p < .01). Self-care deficit had statistical significance in the prediction of complication of pregnancy and baby birthweight (p < .O1). The findings support the validity of Orems self-care deficit theory particularly the part that explained the relationship among environment factor which is a basic conditioning factor, self-care agency, therapeutic self-care demand and self-care deficit with affecting personal life, health and well-being.