The answer, as usual, is it depends. Polygraphs cannot be used in court. Florida case law is clear that a polygraph is never admissible in court because it has not been shown to pass stringent enough scientific standards to be proven reliable. The State may be in possession of a polygraph you have given in your case, but it cannot and will not be used against you at trial or hearing.
However, a polygraph can be used against you by law enforcement for interrogation purposes. Polygraphs are an investigative tool often used in more complex, higher-profile cases. If you have failed a polygraph, a detective can confront you with misinformation you may have given the examiner. Even if you "passed" the polygraph, law enforcement may lie and say that you failed and you might as well confess or tell them the "truth". This, while extremely deceitful, is allowed under Florida case law.
In the end, the best thing to do is not take a polygraph at all. If you fail it, law enforcement will confront you about your lies; if you pass it, law enforcement will likely say you lied anyway. Many think that taking a polygraph is a way to convince cops that you're innocent, but cops often use it as a way to get a confession.
Please do not rely on this information to make a decision in your situation or case: call a lawyer at Soler & Simon at (941) 444-5128 for free consultation.