Obtained by the Houston Astros from the Philadelphia Phillies in as part of the Billy Wagner trade. Astacio got a taste of the big league in posting a 3-6 record with a 5.67 ERA. He pitched 100 innings, striking out 66 and walking 25. Typical of a lot of younger pitchers with a plus fastball, he also gave up an eye opening 25 home runs. He gave up the game-winning home run to Geoff Blum in Game 3 of the 2005 World Series against the Chicago White Sox.
Astacio was claimed off of waivers by the Texas Rangers on March 26, , but he failed to make the team following spring training. After clearing waivers, Astacio was optioned to Triple-A Oklahoma RedHawks. After signing with the Cincinnati Reds organization, Astacio was released before pitching in a game.