We investigated the nitric oxide profile in the plasma of ten healthy controls and 29 patients hurt by the Kobe Earthquake. The levels of nitrite (NO2-) and nitrate (NO3-) were measured simultaneously by high-performance liquid chromatography (HPLC) with UV detection using the Griess reaction after the reduction of nitrate to nitrite. Arginine consumed in food or diet-derived nitrite had no effect on the plasma nitrite and nitrate contents of the healthy volunteers. Plasma nitrate was elevated in the crush syndrome patients; whereas neither nitrite nor nitrate was increased in patients with normal renal function. This finding suggests increased nitric oxide synthesis, decreased excretion of nitric oxide in the crush syndrome or both.