Infantile spasms (IS, West syndrome) represent a difficult to treat and sometimes not immediately recognized form of epilepsy which is relatively rare. West Syndrome or IS is one of the most recognized types of epileptic encephalopathy, a form of epilepsy usually associated with developmental regression and delay, frequently difficult to treat and frequently followed by other types of epilepsy. The spasms themselves are unique in character but may be flexor where the child's arms and trunk seem to bend forward, extensor where arms or shoulders along with the body tend to extend backward momentarily, or they can be mixed. Infantile spasms are an age-related type of seizure and epilepsy syndrome with many causes. In this article, the author discusses the frequency and causes of IS and describes the evaluation of a child with infantile spasms.