A theoretical synthesis of the transition to parenthood of infertile couples is presented. The theory was derived from three studies of infertility the author conducted between 1985 and 1993. The theory is grounded in the experiences of infertile couples, and locates these experiences conceptually in the comparative context of normally fertile couples' transition to parenthood and in the domains of life transitions and illness work. Infertile couples exhibited some of the same processes as their fertile counterparts, varying in the phasing and intensity of these overlapping processes; and, they exhibited processes exclusive to them. There were also intragroup differences in the infertile couples: between adopting and childbearing couples, couples conceiving biomedically and spontaneously, and between couples conceiving with their own or donor gametes. ©1995 John Wiley & Sons, Inc.