Objective Acute pandysautonomia is a rarely seen acquired disorder with acute or subacute development of systemic sympathetic and parasympatheticautonomic dysfunction. Patients may suffer from orthostatic hypotension, bradycardia, anhidrosis, unreactive pupils, ptosis, decreased lacrimation and salivation, gastrointestinal paresis, and impaired genitourinary function. Methods Herein, we present a 15 year-old male patient who underwent laparotomy due to acute abdomen, and suffered from autonomic dysfunction postoperatively. Results The patient had no significant medical history except the laparotomy he underwent a month ago, due to acute appendicitis and ileus. Patient was consulted to neurology because of repetitive syncopes, occurring when he was trying to stand up, and ptosis. A urinary catheter was placed in order to treat globe vesical. Bradycardia (ongoing at sleep) was detected in physical examination, in addition to bilateral ptosis, and absence of deep tendon reflexes. His pupillary reflexes were normal. Blood count, chemical tests, and cardiac sonography didn't reveal any pathologic findings. Electroencephalography and cranial magnetic resonance were also normal. Acetylcholine receptor antibody result was negative, and cerebrospinal fluid protein level was 31.9 mg/dl. 400 mg/kg/day of intravenous immunoglobulin was administered for five days with the diagnosis of acute pandysautonomia. Deep tendon reflexes were reactive, and ptosis, bradycardia and syncopes vanished after treatment. Conclusion Acute pandysautonomia is a rare form of Guillain Barre Syndrome and it is usually seen after an infectious disease or a surgical trauma. Some of these cases may recover spontaneously in childhood. In more severe cases, corticosteroids and intravenous immunoglobulin are effective agents in treatment.