Definition and prevalence of syndrome of functional dyspepsia (SFD) are discussed along with the brief history of the problem, priority works of V.P. Obraztsov and other authors, current views of SFD etiology and pathogenesis with reference to the role of H. pylori infections. Clinical variants of SFD, their diagnostic criteria and principals of differential diagnostics are described. Special attention is given to the debatable relationship between CFD and chronic gastritis. Nosological and syndromal diagnostics, structure-function relationship, goals and methods of SFD treatment and other matters of dispute are considered.