In vivo studies are mandatory to confirm whether a principle generated from in vitro experiments can be reproducible under physiological and pathological conditions, which has become difficult to perform under the principles of 3Rs for animal welfare. Pigs have been expected as an alternative laboratory animal; however, neither regular pigs nor miniature pigs may be suitable for confirming in vivo proof, since they need larger dosage of expensive test articles under developmental phase. Lately, extraordinarily small-sized miniature pigs; namely, microminipigs, weighing approximately 7 kg at 6 months of age when they are young mature, were developed by Fuji Micra Inc. (Shizuoka), which have been provided to several research organizations in Japan as a non-rodent experimental animal optimized for life-science research. We have characterized microminipigs by assessing cardiovascular effects of various drugs and medical devices, and found that most of the cardiovascular responses observed in microminipigs were similar to those in human subjects as well as other non-rodent animals. In this workshop, we will present a brief summary of the development of microminipigs along with recent publications of it in the field of cardiovascular physiology/pharmacology.