Basically, "gentle" means to be kind. "Tender" means to be delicate.

It depend on what you want to say. Sometimes "gentle" and "tender" mean the same thing. For example, a gentle or tender person. Both refer to a kind person. For instance, in the famous song by Elvis Presley, "Love me tender," the meaning would be the same if the song was called "Love me gentle." (Although "love me tenderly" and "love me gently" would confirm to standard grammar.) http://www.youtube.com/watch?v=-Y-bd3aDMGA But both "gentle" and "tender" also have meanings that are not the same.

gentle is the one who treats you nice,tender is the one who gives you every thing and don't cares because this is his nature.