Mejia competed for the men's 4 × 400 m relay at the 2008 Summer Olympics in Beijing, along with his teammates Yoel Tapia, Carlos Yohelin Santa, and Arismendy Peguero. He ran on the third leg of the second heat, with an individual-split time of 46.31 seconds. Mejia and his team finished the relay in last place for a seasonal best time of 3:04.31, failing to advance into the final.