SCIENTIFIC ABSTRACT Cataclysmic variables (CV) include classical and recurrent novae, dwarf novae and symbiotic stars. They are unique laboratories for investigating several important astrophysical processes, including mass-transfer, thermonuclear runaway, dust nucleation and processing, nebular and coronal emission and fine structure line cooling. Most of these processes are accessible only to the satellite infrared. The aim of this proposal is to carry out an investigation of examples of each of the above types of CV, to study (a) the origin, extent and processing of dust in CVs; (b) the energetics of fine structure line emission; (c) the long-term evolution of nova renmnants. OBSERVATION SUMMARY We will perform a study of the infrared properties of CVs using LWS and SWS, CAM and PHOT-S, PHOT-C and PHOT-P. The AOTs have been selected to give a signal-to-noise of at least 10 at the highest wavelength resolution possible, over the wavelength range available with ISO. PHOT-P observations will be used to determine the flux distributions of dwarf novae, classical novae and symbiotic stars. PHOT-S observations of selected classical novae and symbiotic stars will be used to investigate dust emission and the photospheres of CVs with giant secondaries. LWS and SWS observations of selected classical novae and symbiotic stars will investigate nebular, coronal and fine structure line emission, and in particular will resolve ambiguities posed by the inconclusive IRAS broad band observations. Extended emission around classical and recurrent novae with known resolved shells will be carried out with PHOT-C and CAM to investigate the distribution and excitation of molecular, dust and nebular emission. Observation details are in the section "scientific justification". CONCATENATION The intrinsic variability of all the objects in this proposal requires all observations on the same target to be concatenated.