For the women's 100 m, Laenly Phoutthavong went to the 2012 Olympics without a qualifying time or personal best. On 3 August, Phoutthavong completed the third preliminary heat in sixth place and a time of 13.15 seconds. Phoutthavong did not qualify to the next round with her heat placing as she did not finish in the top two in her individual heat. As Phoutthavong did not have one of the two quickest overall times as part of the remaining athletes, she did not advance from the preliminary round. Out of 79 competitors, Phoutthavong was 68th overall during the Olympic event.