Physicians may consider the diagnosis of botulism based on a patient's clinical presentation, which classically includes an acute onset of bilateral cranial neuropathies and symmetric descending weakness. Other key features of botulism include an absence of fever, symmetric neurologic deficits, normal or slow heart rate and normal blood pressure, and no sensory deficits except for blurred vision. A careful history and physical examination is paramount in order to diagnose the type of botulism, as well as to rule out other conditions with similar findings, such as Guillain-Barre syndrome, stroke, and myasthenia gravis. Depending on the type of botulism considered, different tests for diagnosis may be indicated.