SCIENTIFIC ABSTRACT It is proposed to use ISOPHOT to carry out observations leading to a detailed study of the infrared properties of Active Galactic Nuclei (AGN). A combination of broad-band photometry, and photometric mapping will allow a number of important questions on AGN to be addressed. Among others, the size of the far infrared emitting region, the relative importance of the nuclear and extended components at far infrared wavelengths, and the shape of the far infrared spectral turnover in these objects, would all be discussed, with the aim of looking for relationships between the nuclear activity and the host galaxies. We anticipate a total on source integration time for the project of just a few hours, but do foresee that ISOPHOT will in turn make a definitive con tribution in all these issues. OBSERVATION SUMMARY Broad-band mid-IR photometry (PHOT--P), and photometric array mapping (PHOT--C), out to 200 micron in order to both discriminate between the extended and point sources, and to determine the relative importance of each one of these at different wavelengths. The 135, 180, and 200 micron points are of utmost importance, as they will probe an up to now unexplored spectral region. These measurements will also provide the continuum energy distribution of each object in the sample. Two AOTs will be employed, namely P03 and P22. With P03 4 filter settings will be used, 10, 11.5, 16, and 25 micron. For P22 6 filters will be used for imaging with the C arrays. These filters are 60, 90, 120, 135, 180, and 200 micron. An aperture of 120" will be employed avoiding the time consuming peaking process. In most instances staring mode observing is sufficient as the sources are in general high surface brightness objects. We will set the integration time to 32 seconds to improve the calibration of detector drifts. With such integration times S/N above 30 are obtained in most instances, and at times S/N above a few hundreds are foreseen.