Patients with an unpleasant body odor often consult dermatologists. A dermatologist needs to become familiar with the occurrence and significance of medically related odors. Although body odor may be essentially physiological, and problems with body mal-odor are paid little attention, they can cause many personal troubles and may induce a variety of psychosocial disturbances. Body odor in general is an indicator of individual care and hygiene, or results from eating garlic, onion, spicy foods, curry, or drinking alcohol; however, in some instances it can be pathologic. It is a well-known clinical fact that many diseases (both of internal and cutaneous origin), several syndromes, and some intoxications cause characteristic, peculiar, and identifiable odors. Their identification can provide diagnostic clues, guide the laboratory evaluation, and help in the choice of immediate and appropriate therapy. Thus, olfactory evaluation can be an important part of clinical examination and olfactory diagnosis is still valid in recognizing certain diseases. This report reviews the physiological and pathologic body odors and the importance of olfactory diagnosis in dermatology.