Primary varicella-zoster (VZ) infection is rare in adults, but the rate of morbidity and mortality is higher than in children. Pneumonia is the most common complication of primary VZ infection in adults. Moreover, varicella pneumonia associated with acute renal failure and acute encephalopathy is very rare. This study reports on a case of disseminated VZ infection successfully treated with acyclovir. The patient was otherwise healthy and denied previous systemic or infectious disease. The initial diagnosis was varicella pneumonia. However, multiple organ involvement subsequently was found in several organs, including the kidney, brain, lung, liver, blood, and skin. The reactivation of VZ infection was strongly suspected. Abnormal renal and liver function and thrombocytopenia also were noted. The patient with chickenpox was treated successfully with acyclovir without complication. In conclusion, multiple organ involvement is a rare complication of VZ infection in adults. In the severe case presented here, adequate intravenous acyclovir administration and close observation of the general condition were essential for successfully treating disseminated VZ infection without complications.