For timely monitoring of internally contaminated individuals following radiological or nuclear emergency events, two fast bioassay methods were developed for the measurement of 239Pu in faecal samples, one for a sample representing 24-hour excretion and the other for a sample representing 10% of 24-hour excretion. Samples were decomposed either by ashing/microwave digestion or by acid refluxing. They were measured by ICP-MS following solid phase extraction using TEVA resin from Eichrom®. The two methods were assessed against performance criteria for radionuclide bioassay defined by ANSI N13.30 for their accuracy and repeatability. Both methods satisfy the requirements and are sensitive enough for emergency population screening. The method for small samples has a much shorter sample turnaround time, making its application more promising.