The diagnosis of Amyotrophic lateral sclerosis (ALS) remains in 2010 clinical with neurophysiological support in absence of specific biomarker(s). The disease is diverse in its presentation, cause, and progression. Treatable mimic syndromes must be excluded before the diagnosis is ascribed: ALS and its variants are recognized by neurologists, but 10% of patients are misdiagnosed. Delays in diagnosis are common. Less than 10% of cases are familial and associated with several interactive genes. The onset of ALS predates development of the clinical symptoms by an unknown interval which may extend several years. Prompt diagnosis, sensitive communication of the diagnosis, the involvement of the patient and family, a positive care plan are pre-requisites for the good clinical management of ALS patients.