Although gastrointestinal complications have decreased dramatically in patients with acquired immunodeficiency syndrome (AIDS) who received highly active antiretroviral therapy, these disorders still occur in those who do not seek healthcare, those with resistant virus, and those in developing countries where these drugs are not available. Opportunistic infections are the most frequent causes of gastrointestinal disease in patients with AIDS. A practical approach based on the character of the complaints and location of symptoms will help direct the most appropriate evaluation. In most patients, a diagnosis should be sought because effective antimicrobial therapy is available for most infections in these patients. When possible, improvement in immune function forms an integral part of the treatment regimen.