The introductory volume of the Handbook of Work and Organizational Psychology is concerned with definitional, historical and methodological fundamentals. It explores the nature of studies in work and organizational psychology; the role played by the professional psychologist; and the ways in which the discipline has developed within Europe. The editors attempt to characterize the domain of work and organizational psychology, and examine relations between this and other subdisciplines within psychology, as well as those disciplines outside psychology also concerned with work and organization.