Antenatal Care has important role in reducing the number of maternal illness and death. Low number of fourth visit in antenatal care (K4) indicates the weak effort in controlling high risk pregnancy. Based on consumer's buying decision process, this research aimed to analyze why fourth visit in antenatal care in Puskesmas Tembok Dukuh decrease. This is a crosssectional research with quantitative methods. 80 mothers who had given birth in March to June 2012 were participated. The questionnaires distributed to dig up mother's characteristics (demographic, socioeconomic, and psychographic) and their buying decision (buying process, purchasing decision, post-purchasing behavior). The results of this research are: (1) the major buying process were needs identification, information-searching and alternatives evaluation, (2) there was no difference between the self decision and other's decision-making, (3) most of them used previous health service for their fourth visit antenatal care, (4) the low support of psychographic about antenatal care, the unmet needs for antenatal care, no accurate information about antenatal place, type of action, and benefits of each action during antenatal care, and facilities are unsatisfactory were factors which contribute to the mother absent in fourth visit antenatal care, (5)generally post-purchasing behavior was good.