Large animal models have been widely used to facilitate the translation of mesenchymal stem cells (MSC) from the laboratory to patient. MSC, with their multi-potent capacity, have been proposed to have therapeutic benefits in a number of pathological conditions. Laboratory studies allow the investigation of cellular and molecular interactions, while small animal models allow initial 'proof of concept' experiments. Large animals (dogs, pigs, sheep, goats and horses) are more similar physiologically and structurally to man. These models have allowed clinically relevant assessments of safety, efficacy and dosing of different MSC sources prior to clinical trials. In this review, we recapitulate the use of large animal models to facilitate the use of MSC to treat myocardial infarction-an example of one large animal model being considered the 'gold standard' for research and osteoarthritis-an example of the complexities of using different large animal models in a multifactorial disease. These examples show how large animals can provide a research platform that can be used to evaluate the value of cell-based therapies and facilitate the process of 'bench to bedside'. Keywords Mesenchymal stem cell. Large animal. Osteoarthritis. Myocardial infarction 'large' animal models). An animal is considered a 'large animal' when the species in question is non rodent, rabbit or guinea pig (Thomas et al. 2012). The more commonly used large animal models in research include horses, cows, pigs, sheep, goats, primates and dogs, and the choice of animal model depends on multiple factors, including