Systemic capillary leak syndrome (SCLS) is characterized by recurrent hypovolemic shock attributable to increased systemic capillary leakage. A 46-year-old man was admitted to our hospital because of recurrent episodes of generalized edema with hypovolemic shock. Blood laboratory data revealed severe hypoproteinemia with a small monoclonal IgG-kappa protein. These findings suggested strongly the diagnosis of SCLS. A regimen with steroid pulse therapy was tried; however, intravascular overloading accompanied by the recruitment of the initially extravasated fluids resulted in acute pulmonary edema. Intensive care and careful monitoring of fluid volume are required in SCLS.