Systolic and diastolic dysfunction of the left ventricle (LV) is a hallmark of most cardiac diseases. In vivo assessment of heart function in animal models, particularly mice, is essential to refining our understanding of cardiovascular disease processes. Ultrasound echocardiography has emerged as a powerful, noninvasive tool to serially monitor cardiac performance and map the progression of heart dysfunction in murine injury models. This review covers current applications of small animal echocardiography, as well as emerging technologies that improve evaluation of LV function. In particular, we describe speckle-tracking imaging-based regional LV analysis, a recent advancement in murine echocardiography with proven clinical utility. This sensitive measure enables an early detection of subtle myocardial defects before global dysfunction in genetically engineered and rodent surgical injury models. Novel visualization technologies that allow in-depth phenotypic assessment of small animal models, including perfusion imaging and fetal echocardiography, are also discussed. As imaging capabilities continue to improve, murine echocardiography will remain a critical component of the investigator's armamentarium in translating animal data to enhanced clinical treatment of cardiovascular diseases. murine echocardiography; systolic and diastolic function; speckle-tracking imaging; strain analysis; heart failure THIS ARTICLE is part of a collection on Assessing Cardiovascular Function in Mice: New Developments and Methods. Other articles appearing in this collection, as well as a full archive of all collections, can be found online at http://ajpheart.physiology.org/.Rodents are invaluable models for cardiovascular research, in part because of the extensive knowledge of their genome, homogeneity of study population, reproducible pathological phenotypes, and relative ease of creating genetically modified models. Surgical techniques that induce myocardial overload, infarction, and dysfunction in mice and rats have enabled a reliable identification and assessment of key physiological, molecular, and biochemical mechanisms of cardiovascular diseases (43). With the use of noninvasive imaging tools such as ultrasound echocardiography, cardiovascular evaluation of rodents has further led to the translational development of new diagnostic techniques and therapeutic strategies to predict and prevent cardiovascular disease complications in humans (82).Echocardiography remains a gold standard for a reliable assessment of cardiovascular structure and function in humans (19). The technology's allure lies primarily in its portability, relative affordability, widespread availability, noninvasive nature, and rapid real-time imaging capabilities. With advancements in clinical echocardiography, the technicalities and conceptual framework of the methodology and equipment have been extended from humans to small animals. Ultrasound imaging greatly facilitates the evaluation of cardiac function in transgenic animals, as well as surgically induced ...