At the 2012 Summer Olympics in London, Lalova finished second in her heat during the quarterfinals on Women's 100 Metres, equaling her season best of 11.06. She was eliminated in the semifinals, where she ran the distance for 11.31, finishing 6th in her heat and 19th overall. At the 200 metres distance she finished 5th in her heat with a season-best time of 22.91. In the semifinals she ran the distance for 22.98, finishing 6th in her heat and missing on a place in the final.