This document presents the results of the 2001 Research Assessment Exercise (RAE). The RAE, which operates through a process of peer review by experts, is designed to provide ratings of the quality of research conducted at universities and higher education colleges in the United Kingdom. The ratings are used to inform the allocation of funds and to promote high quality in research. A total of 173 institutions took part in the 2001 RAE, and almost 300 international experts from outside the United Kingdom provided independent verification of the results. The results indicate improvements in the overall quality and international standing of research carried out in the universities and colleges of the United Kingdom. They show high quality research in a large number of institutions. Sixty-one institutions have one or more departments with the highest rating (5*), and 96 have a department rated "5." Findings show that 55% of research-active staff now work in the top-rated 5 or 5* departments, compared with 31% in 1996. There has been an increase in the volume of research that corresponds to national or international levels of excellence. Results of the 2001 RAE confirm the United Kingdom's position as one of the world's foremost research nations. UK researchers rank first in the world in terns of the numbers of publications and citations generated per million dollars spent on research. Results of the RAE are presented in table form for the United Kingdom as a whole and by the unit of assessment for 111 disciplines. An institutional research profile with two graphs is included for each of the participating institutions. (SLD)