This book reported the literature survey of the chemistry of pyrido 1,2-a]pyrimidines. In this context, all the synthetic methods used for the preparation of pyrido 1,2-a]pyrimidines which considered as an important moiety in the field of organic synthesis, were reported. In addition, the biological activities and synthetic applications were discussed. The reactions of pyrido 1,2-a]pyrimidine compounds were reported. The type of its reactions include electrophilic (i.e. coupling, acetylation, alkylation, formylation, nitrosation and halogenations), condensation, ring transformation, ring...