The improved stratospheric and mesospheric sounder (ISAMS) on the Upper Atmosphere Research Satellite (UARS) made some of the first global measurements of dinitrogen pentoxide (N2O5) in the 1991/1992 period. N2O5 is a crucial part of the ozone photochemical cycle in the stratosphere, but measurements of its variability and distribution are difficult and hitherto have been rare, inhibiting adequate testing of dynamical-chemical models of the stratosphere. This paper describes the production and validation of the first set of ISAMS global N2O5 data to be made publically available (version 10). It is concluded that the results represent a considerable improvement over those previously available and are ready for use in certain kinds of scientific work. There still exist problems regarding the treatment of stratospheric sulfate aerosol which further processing will hopefully resolve. ¿ American Geophysical Union 1996