Abstract Previous studies have suggested a lower incidence of ALS in people of African origin. We used a population based register in an urban setting from inner city London postcodes where there is a large population of people of African ancestry to compare the frequency of ALS in people of European and African origin. Population statistics stratified by age, gender and ethnicity were obtained from the 2001 census. Incidence and prevalence were calculated in each ethnic group. Results showed that in a population of 683,194, of which 22% were of African ancestry, 88 individuals with ALS were identified over a seven-year period, including 14 people with African ancestry. The adjusted incidence in people of African ancestry was 1.35 per 100,000 person-years (95% CI 0.72-2.3) and in those of European ancestry 1.97 per 100,000 person-years (95% CI 1.55-2.48). In conclusion, in this small population based study we could not detect a difference in rates of ALS between people of African ancestry and those of European ancestry.