Infertility, defined as failure to achieve pregnancy within 12 months of unprotected intercourse or therapeutic donor insemination in women younger than 35 years or within 6 months in women older than 35 years, affects up to 15% of couples. An infertility evaluation may be offered to any patient who by definition has infertility or is at high risk of infertility. Women older than 35 years should receive an expedited evaluation and undergo treatment after 6 months of failed attempts to become pregnant or earlier, if clinically indicated. In women older than 40 years, more immediate evaluation and treatment are warranted. If a woman has a condition known to cause infertility, the obstetrician-gynecologist should offer immediate evaluation. Essential components of an initial workup include a review of the medical history, physical examination, and additional tests as indicated. For the female partner, tests will focus on ovarian reserve, ovulatory function, and structural abnormalities. Imaging of the reproductive organs provides valuable information on conditions that affect fertility. Imaging modalities can detect tubal patency and pelvic pathology and assess ovarian reserve. Male factor is a cause of infertility in 40-50% of couples. Given the high prevalence of male factor in infertile heterosexual couples, a basic medical history and evaluation of the male partner are warranted from the outset. A women's health specialist may reasonably obtain the male partner's medical history and order the semen analysis. It is also reasonable to refer all male infertility patients to a specialist with expertise in male reproductive medicine. Unexplained infertility may be diagnosed in as many as 30% of infertile couples. At a minimum, these patients should have evidence of ovulation, tubal patency, and a normal semen analysis.