In this paper, the author argues that evaluation theory and practice interact insufficiently today, even though early evaluation theorists expected them to be closely intertwined. She views this limited connection as the result of differing interests on the part of theorists and practitioners, differing frequencies of dissemination, and differing targets of opportunity, with theorists concentrating often on methodological processes internal to evaluation, and practitioners more concerned with the application of these processes to an external environment. The author provides examples taken from current evaluation practice in which theory is largely ignored, as well as instances of theoretical writing which fail to consider problems faced by practitioners in their efforts to accommodate current theory. These examples are chosen among many which commonly occur across the planning, implementation and reporting phases of an evaluation in progress. The likely implications of this still unfulfilled relationship for the development of the evaluation field are discussed and some potential ways forward are described.