To investigate the yield of routine thyroid function testing in infertile women, the records of 444 infertile women were categorized to standard infertility groups. Thyroid function was evaluated by measuring plasma free thyroxine and thyroid-stimulating hormone. All free thyroxine values were in the normal range (0.8 to 1.8 ng/ml), and only three thyroid-stimulating hormone values were higher than the normal range (0.15 to 4.5 mIU/L). The three women had ovulatory dysfunction. Thyroid function testing is more prudent in screening the subset of infertile women with ovulatory dysfunction and not as a routine measure in the infertile population.