The long-term prognosis of 58 untreated infertile couples with normal medical histories and physical examinations, and normal basic infertility investigations, including biphasic basal body temperature, hysterosalpingogram, postcoital test, and semen analysis, was studied using life-table analysis. Of these women, 34% were pregnant by six months, 76% by two years, and 87% by five years. These rates of conception were found to be significantly higher than those found in a large infertile population (P=.001). However, compared with the ideal fertile population, the study group for the first two years had a significantly lower conception rate (P=.001). It required two years for the study group to achieve a 74% fertility rate, whereas only nine months were required for the fertile group to achieve the same rate. The individualized approach for investigating the infertile couple is stressed.