Intravenous injection of crude marijuana extract led to development of an acute illness with multisystem involvement. Gastrointestinal manifestations consisted of severe vomiting, diarrhea, and crampy abdominal pain. Hypotension, tachycardia, and peripheral vasodilation constituted the main cardiovascular manifestations of the disease. Moderate azotemia and oliguria, presumed to be of prerenal origin, were present and rapidly resolved with administration of intravenous fluids. Hematologic manifestations consisted of leukocytosis with a left shift, thrombocytopenia, prolonged partial thromboplastin time, increased fibrin degradation products, and positive protamine sulfate test. The observed coagulation abnormalities may suggest intravascular coagulation. C3, C4, and total hemolytic complement were reduced, suggesting possible activation of the complement system. Hyperventilation, hypoxemia, pulmonary edema, obstructive, and restrictive pulmonary function abnormalities and bilateral pleural effusions highlighted the pulmonary manifestations of the disease. Rhadbomyolysis and mild hepatic function abnormalities were also present. All observed abnormalities reversed in a few days with no significant sequelae.