Board Thread:Naruto Discussions/@comment-25374031-20140917212238/@comment-5407586-20140917220350

No. Jiraiya, as stated by Fukasaku, was unable to perfectly balance physical, spiritual and natural energies, and as such couldn't enter a "perfect" Sage Mode. According to Fukasaku, one becomes a "true" Sage when the only physical changes are the markings around the eyes (and the horns in Kabuto's case).