Some possible reasons for the historical absence of psychoanalytic outcome research are examined, particularly the incompatibilities in the world view espoused by psychoanalysis and that of most of current science and the assumption of privileged knowledge on the part of many psychoanalysts and their training institutions. It is argued that the view that psychoanalysis offers an alternative epistemology to that of scientific research maintains psychoanalysis in its inferior position. The existing evidence for the effectiveness of adult psychoanalytic psychotherapy is reviewed and the relevance of these findings to child psychotherapy outlined. Finally the author proposes a research agenda for both child and adult psychotherapy and outlines the changes that psychotherapists will need to make if they are to implement this agenda.