The cautionary jury instruction came into American jurisprudence from the English common law. It reflects society's assumption that those who complain of rape often lie. Most cautionary instructions contain three elements: the ease with which a victim can charge rape; the difficulty for a defendant to disprove the charge of rape; the extra scrutiny required of the rape victim's testimony. While five States have enacted legislation prohibiting the cautionary instruction, more than half of the States still permit the cautionary instruction at the conclusion of a rape trial. The article argues that the cautionary instruction is obsolete, usurps the function of the jury, damages the credibility of the rape victim at trial, and represents an impermissible comment on the evidence. 145 footnotes.