Red raspberry leaf (Rubus spp.) has been historically used as an herbal medicine to promote labor as well as to reduce pain during childbirth. Previous research has shown red raspberry leaf (RRL) to either contract or relax uterine smooth muscle tissues. These variable responses are likely a function of the species used, the stage of estrous, whether the protocols were completed on intact organisms or isolated tissues, how the extracts were prepared, as well as the concentrations administered. The purpose of this investigation was to collect data using contemporary techniques that either supported or refuted claims that RRL contracts isolated uterine muscle. Aqueous extracts of RRL at all concentrations tested (1.5 - 50 mg) produced increases in contractile forces from isolated longitudinal strips of mouse uterine tissues suspended in standard 15 mL organ baths. The responses were concentration-dependent when presented as a standardized contractile response to10⁻⁵ M ACh (p = 0.005), and were equal in magnitude or slightly greater than those induced by 10⁻⁵ M ACh. Both cholinergic nicotinic and muscarinic receptor antagonists failed to block RRL induced contractions. Salbutamol prevented any contractile response from RRL; however, the β₂ antagonist propranolol successfully blocked the salbutamol induced-relaxation response and allowed RRL contractions, implying there may be a constituent in RRL that interacts with some functional component of the β₂ adrenoceptor. The L-type Ca² channel blocker nifedipine blocked RRL induced contractile responses by 90%. This study provides empirical evidence for the traditional use RRL as an herbal uterotonic. It does not however, address the relative effectiveness of ingested RRL on the labor and birth processes.