On November 4, 2006, he defeated Robert Guerrero for the IBF featherweight title, by a unanimous decision. The official scorecards read 115-113, 118-110, 117-111. Salido's win over Guerrero was later overturned, as Salido tested positive for steroids after the fight. As a result of his positive test for Nandrolone (an anabolic steroid that may be present naturally in the human body in minute quantities), Salido was stripped of his title and faced disciplinary action in Nevada, which included a suspension. Salido maintained his innocence and immediately had a follow up test at LabCorp, a nationally recognized blood lab. The findings were negative of any steroids.