Black people are three times more likely to have a Taser used against them than white people, figures suggest.
The weapon has been used by police thousands of times in the past five years, with a rise in its use against children, the Home Office data showed.
Tasers were used - meaning they were drawn, aimed or fired - by police 38,135 times between 2010 and 2015, a BBC freedom of information request showed.
In 80% of cases the weapon was not discharged.
In over 12% of cases in which ethnicity was recorded - more than 36,000 of the 38,000 incidents - the person against whom the Taser was used was black and of African-Caribbean origin or of mixed white and African-Caribbean origin.
A Taser was used against people under the age of 18 in 522 cases, compared with 349 times in 2010.
In February the Police Federation voted for all uniformed officers to be issued with Tasers.
There were 158 cases last year involving children under 16, the figures showed.
In one case in Hampshire a police officer removed his Taser from the holster in an incident involving a nine-year-old boy.
In another a Taser was drawn against a 91-year-old man, according to the Home Office figures. However Suffolk Police said they could find no record of it.