Temalangeni Dlamini was 21 years old at the time of the Beijing Olympics and was making her debut in Olympic competition. On 16 August, she participated in the heats of the women's 400 meters, and was drawn into heat seven. She finished her heat in a time of 59.91 seconds, seventh and last in her heat, over nine seconds behind the heat's winner, Shericka Williams of Jamaica, and was eliminated from the competition. The gold medal was eventually won by Christine Ohuruogu of Great Britain in 49.62 seconds, the silver by Williams, and the bronze medal was taken by Sanya Richards-Ross of the United States.