Headspace solid-phase microextraction, followed by GC-MS analysis is presented as a suitable technique for the determination of musk compounds in sewage treatment plant sludge. Five polycyclic musks (celestolide, phantolide, traseolide, galaxolide and tonalide) and four nitro musks (musk xylene, musk moskene, musk tibetene and musk ketone) were considered in the optimisation of the analytical method. The influence of extraction temperature, fibre coating, agitation, pH and salting out on the efficiency of the extraction along with the extraction kinetics were studied. An extraction temperature of 100 degrees C and sampling the headspace over the stirred sludge sample using polydimethylsiloxane -divinylbenzene as fibre coating lead to effective extraction. The method proposed is very simple and yields high sensitivity, good linearity and repeatability for all the analytes with limits of detection at the sub-ng/g level. The total analysis time, including extraction and GC analysis, was only 40 min, and no manipulation of the sample was required.