Rapid HIV tests were conducted on almost 300 people when a mobile clinic toured the borough during a 10-day campaign to encourage people to get checked for the condition.
National HIV Testing Week ran from 22 November until World Aids Day on 1 December.
A mobile clinic visited West Croydon, Thornton Heath, Norbury, South Norwood, New Addington and North End in central Croydon, with 286 people getting tested.
People were able to turn up, get tested and find out the result in 15 minutes.
In Croydon, more than half of people with HIV get diagnosed late, and almost 30% get diagnosed very late when their immune systems have already been damaged, which can lead to serious ill health.
However, if caught early, people can receive treatment to live a long and healthy life.
Councillor Margaret Mead, cabinet member for adult services and health, said: “By going out into communities we were aiming to reach people who might not normally have an HIV test.
“We’re delighted with the high number of people who had a test. This campaign was about letting people know that the sooner they know they are infected, the quicker they can be treated before the onset of serious health problems.”
For those who missed the mobile clinic, testing is available all year round at the Croydon Sexual Health Centre at Croydon University Hospital, and on Fridays between 2pm and 6pm at Edridge Road Community Health Centre, Croydon.
For more information visit www.swish.nhs.uk