Infertility is a disease that exists when a couple has tried to conceive for 12 months during which time they have had intercourse without the use of contraception. The fecundability of a normal couple in one cycle has been estimated at 20% to 25%. On the basis of this estimate, about 85% of couples should conceive after 12 months of unprotected intercourse. Infertility affects about 13.5% of reproductive couples in Korea. Earlier evaluation and treatment is required in women with age over 35 years and some medical conditions. Both partners should be evaluated at the same time. The use of a standard infertility treatment algorithm results in a higher pregnancy rate and lower cost and therefore should be the preferred treatment approach. IVF-ET and tubal surgery must be considered to be complementary rather than competitive procedures. Adequate selection of patients is crucial to find the best therapeutic approach.