In 1977, the Missouri legislature enacted House Bill 502, which is designed to substantially limit the admissibility of evidence of the prior sexual conduct of the complaining witness in rape prosecutions. The statute wholly rejects the use of opinion and reputation evidence concerning the prior sexual conduct of the witness. Evidence of specific instances of such conduct is admissible only under certain limited circumstances and to the extent that it is deemed relevant. Furthermore, the admissibility of this limited evidence must be approved by a process of hearings held by the court upon written notice and offer of proof by the defendant. These new standards go far to remedy the prior practice which subjected the complaining witness in a rape prosecution to an unjustified invasion of privacy for the purpose of displaying unfairly prejudicial facts to the jury. The Missouri rape evidence reform statute is part of a nationwide pattern of similar statutes limiting the admissibility of this type of evidence. At least 24 States now have such laws. The practical effect of the bill will depend largely on the use of discretion left to the courts by the statute. The defendant will still have every other normal means of impeachment of the victim. Character evidence relating to veracity remains admissible for impeachment purposes. The statute's effectiveness in limiting admission of sexual conduct materials will be determined by the trial judge's interpretation of terms such as 'reasonably contemporaneous', 'immediate surrounding circumstances', and 'relevancy'. With regard to the constitutionality of the statute, due process rights of the defendant do not require the admission of evidence which is unfairly prejudicial. The rape evidence reform statute serves the paramount State interest in the conviction of a criminal based on a fair presentation of the evidence. The article includes 113 footnotes.