This study examines the influence of scientists motivations and the organisational environment in which they work, on scientific research effectiveness. The study presents relevant literature on existing perspectives of scientific effectiveness as well as literature on the organisation of scientific research and motivation theory. Building on existing literature in these areas a new model of scientific effectiveness is presented that attempts to explain scientific effectiveness through the interaction of scientists motivations and the organisational environment in which they work. The study describes the selection and development of new measurement instruments used to operationalise the variables contained withm this model Results of data collected from 330 research active scientists in 20 UK universities are analysed. Results are discussed in relation to the model under examination, and the new measurement instruments developed during the course of the study. Limitations of the current study are presented and recommendations for future research are made.