The unanimous acquittal instruction requires that judges instruct juries to return a unanimous verdict of not guilty on the charged offense prior to considering any lesser included offenses. Courts supporting the unanimous acquittal rule point out that the instruction enables all jurors to express their views fully on the evidence presented at trial, for they all must agree to acquit the defendant on the charged offenses before rendering a final verdict on any of the lesser included offenses. Courts giving the disagreement instruction permit consideration of lesser included offenses when the jury cannot agree whether conviction of the greater offense is appropriate. While the disagreement instruction may make juries more efficient, it also makes them more likely to compromise. The article examines research on jury behavior and concludes that all courts should adopt the unanimous acquittal rule because it preserves the integrity of jury deliberations. 175 footnotes.