Aguilar first tried his hand at smaller tournaments of the ITF Futures Tour in the Americas. In January 2003, he made it to the finals of El Salvador, where he lost to Alejandro Falla. In June 2004, followed by another final in the United States, there was defeated Michael Russell 3-6, 0-6. In January 2005 he made his debut on the ATP Challenger Tour in his hometown and managed was immediately awarded the semi-finals. In April, he had once again beaten in a final Juan Martín del Potro at a Futures tournament. His first playoff outside America reached Aguilar in June 2005 in Arad, where he lost to local hero Victor Crivoi 1:6, 2:6.
In January 2006, the Chilean was at his home tournament in Vina del Mar made his debut on the ATP Tour, and defeated in the first round his compatriot Guillermo Hormazabal. In round two, he had to Leoš Friedl beaten. After two more Finaleinzügen finally succeeded in August 2006, the first title on the Futures Tour in Mexico, where Aguilar came through the competition without dropping a set. In November another title followed in Chile. Well appearances were more frequent on the Challenger tour, but rarely Aguilar came out on the first round.
In October 2007, he won another Future in Chile, two months later he repeated this triumph. In October 2008, Aguilar was also able to win two tournaments in his home, another title followed in November in Peru. In May 2005, he won another tournament in Argentina, during the year added Aguilar his collection of titles, five other futures Trofäen added. At the French Open 2010, he fought his way through qualifying, but lost in the first round against Tomas Berdych in three sets. On July 9, Aguilar made his debut in the Davis Cup World Group quarter-final, where he defeated Lukáš Dlouhy 6-1, 7-6. End of June 2011 Aguilar won his so far last Futures tournament in France, so he has to date 14 items can collect on the Futures Tour.