The object of this study was to develop a theory of the relationship between a mother and her unborn twins using a qualitative grounded theory methodology. Ten women participated in interviews during the last trimester of a twin pregnancy and again during the early postpartum period. Data provided by these women was analysed using the constant comparative method. Two additional informants were sampled in order to formulate and verify the tentative theory. For women in this study, the findings indicate that mothers from a relationship with their unborn twins within the wider context of accommodating the twin pregnancy in their lives. A woman accomplishes this process by immediately seeking information about twin pregnancy, by making room, in all senses, for two babies instead of one in her life, and by appraising her own pregnancy risk. A mother engages in self-protective behaviors and in behaviors designed to protect the health of her unborn twins as a method of coping with the perceived risk of the twin pregnancy and with the twin pregnancy itself. As the twin pregnancy progresses, women move toward accepting the idea of being pregnant with twins. For women pregnant with twins, the birth of two infants confirms the reality of the pregnancy.