The prevalence and incidence of amyotrophic lateral sclerosis (ALS) is not fully established, and this varies depending on the studied population.To estimate the prevalence/incidence of ALS patients in Antioquia-Colombia.Observational/descriptive study by reviewing clinical records from 2010 to 2014. Cases with possible, probable and definite ALS were included. To estimate the prevalence/incidence, capture-recapture method was used.Point prevalence in December 2014 was 4.9/100,000 (95% CI 2.0-7.8), and the incidence was 1.4/100,000/year (95% CI 0.5-2.2). The median survival was 4 years. Spinal-onset was observed in 62.4% of the included patients.Prevalence, incidence and clinical presentation of ALS in Antioquia are similar to most studies reported worldwide. However, prevalence in Antioquia seems to be slightly higher than in other studies from Latin -American countries. This may derive from the inclusion criteria and case detection methodology adopted, but sociodemographic and genetic factors should be considered.