If you dream of taking a polygraph (lie detector) test, the meaning depends on whether or not you were lying in the dream.
If you were, ask yourself what you’re hiding from yourself or others. Deep inside, you want the truth to be known.
If you were accused unjustly, you will be annoyed by a troublesome person.
If you dreamed of someone else taking a lie detector test, you may find help from an unexpected source in some situation.