This paper describes the low-frequency noise behaviour of n-channel MOSFETs fabricated in a 0.1 mu m technology. It is shown that the spectra are predominantly of the l/f-type for some part of the frequency range investigated. For some devices, two l/f-type parts occur, one at low and another at "high" frequencies. separated by a plateau. A careful analysis of the drain current or gate bias dependence of the noise spectral density reveals that the low-frequency l/f-type noise is governed by the fluctuations in the series resistance region of the devices. The corresponding Hooge parameter alpha(H) is of the order of 10(-4). For the l/f-like noise occurring at "high" frequencies, it is observed that it can be ascribed to fluctuations in the channel, giving rise to a high value of alpha(H) of similar to 10(-3) (from 2.5 x 10(-3)-8 x 10(-3)).