We examine the extent to which galactic and extragalactic foregrounds car, hamper the detection of primordial Cosmic Microwave Background (CMB) anisotropies. We limit our discussion to intermediate angular scales, 10' less than or similar to theta less than or similar to 2 degrees, since many current as well as future experiments have been designed to map CMB anisotropies at these angular scales. In fact, scales of greater than or similar to 10' are of crucial importance to test both the conditions in the early Universe and current theories of the gravitational collapse.
