This chapter provides an overview of Game Theory with applications to medicine problems, including evolution of tumor cells and their competition, applications to neocortical epilepsy surgery and schizophrenic brain. Recent studies related to microarray games for cancer problems will be considered. These models may be used for applications to neurological and allergic diseases. At the end, the model of kidney exchange via the Matching Theory proposed by Alvin Roth, Nobel prize 2012, will be discussed.