Amandasgirl, what happens to you if you fail a probation drug test depends on many things. First it depends on which state you live in and even which county and which judge you were sentenced by and even your probation officer. It depends on the original charge, felony or misd., drug related or not. Then it will also depend on if you have been doing everything else you are supposed to do such as paying court costs and fines, going to probation meetings, going to any "classes" they may make you go to, if this is the first drug test failed, etc. Your first failed test punishment could range from nothing but a warning to picking up trash on the highway for a weekend (in my state if you are in drug court this is an option) to a few hours in jail one weekend, to being sentenced to jail or prison time on the original charge. It all depends. Amandasgirl79 it is impossible to know and especially since you haven't really given that much info.