Mucocutaneous lymph node syndrome (MLNS) has been accepted in Japan as a newly recognized disease affecting most frequently patients under 5 years of age. It is now apparent that the syndrome, having been defined, is also recognized with increasing frequency in the continental United States and Canada in children of non-Japanese ancestry. MLNS is characterized by (1) fever, (2) bilateral congestion of the conjunctivae, (3) changes in the oral cavity, consisting of strawberry tongue, erythema of the oral mucosa, and sicca of the lips, (4) indurative edema and erythema of the hands and feet followed by desquamation of the fingertips, (5) polymorphous exanthema, and (6) cervical lymphadenopathy. The clinical signs and symptoms are somewhat reminiscent of other related conditions. To prevent potentially fatal cardiac complications associated with MLNS, prompt and accurate diagnosis is imperative so that the patient may be referred to a physician for careful monitoring during convalescence.