  Surveys with ISO (Kessler et al 1996), in particular with the CAM (Cesarsky
et al 1996) and PHOT (Lemke et al 1996) instruments, will greatly extend our
understanding of extra-galactic populations and their cosmological evolution.
The main advantages that ISO surveys have over e.g IRAS are increased
sensitivity/depth and wavelength coverage. Within the Guaranteed and Open Time
programmes there are many field surveys which will efficiently map the limits
in these parameters. In this talk I will briefly overview those surveys before
concentrating in more detail on one survey in particular, the ISO survey of the
Hubble Deep Field (HDF), to illustrate the kind of results that can be
expected.

Astrophysics