Leiva debuted in the
LNB (Argentine 1st Division) on 12 October 1997, playing for
Ferro Carril Oeste, against
Independiente de General Pico. He played four seasons with Ferro, and then 6 with
Boca Juniors in the top division. With Boca, he won the 2003–04 and 2006–07 seasons of the LNB. and the following season for
Baloncesto León, both in the
LEB (Spanish 2nd Division). In 2009, he returned to Argentina, signing for
Peñarol de Mar del Plata. Upon his return, he helped the team win the 2009–10 and 2010–11 seasons of the LNB, as well as the 2009–10
FIBA Americas League. On 30 September 2019, Leiva returned to Boca Juniors. ==National team career==