The article first describes the theory of battered woman syndrome and its use in the claim of self-defense in a homicide case. This is followed by a review of the admissibility of expert testimony on battered woman syndrome as evidence in homicide cases and includes an analysis of criteria for admission. The final section analyzes State v. Hennum and limitations on admitted testimony based on the ultimate issue rule. When the ultimate issue rule was in effect, it prevented witnesses from the expression of an opinion on issues the trier of fact ultimately decides. The Federal Rule of Evidence 704 supplanted the ultimate issue rule in its designation that opinion testimony can only be excluded if it amounts to a witness' conclusion on how the case should be decided. In "Hennum," the Minnesota Supreme Court found that expert testimony on battered woman syndrome assists the jury in understanding a phenomenon beyond their understanding. Moreover, the court held that battered woman syndrome has gained "substantial enough scientific acceptance to warrant admissibility." The court, however, fashioned a rule that limits experts who testify on battered woman syndrome to general testimony on the syndrome and the characteristics exhibited by a typical sufferer. The court did not permit a qualified expert to testify to the ultimate fact that the defendant suffered from battered woman syndrome. The court erred in this ruling; a court should not exclude expert testimony that simply identifies a defendant as a sufferer of battered woman syndrome. 261 footnotes