Amenorrhea is a complicated and common problem encountered by primary care physicians. Performing a thorough history and physical examination can often narrow the differential diagnosis considerably. The addition of basic determinations of serum FSH and LH or other tests as indicated by abnormalities on the history or examination can then make the diagnosis more clear. In all cases of primary amenorrhea, treatment is directed by the diagnosis. The primary goal of treatment is to facilitate the normal sexual development through gentle coaxing into puberty. In secondary amenorrhea, there is a greater focus on fertility and prevention of complications from the associated abnormal hormone levels. Probability of conception is dictated by the reversibility of the cause of the amenorrhea.