The concentration of the radionuclides103Ru,134Cs and137Cs in sewage sludge samples which were collected between July and September 1986, were measured by -ray spectrometry. High concentration of103Ru,134Cs and137Cs were found in sewage sludge samples from Lower-Austria /Scheibbs, Zwettl/ and Styria /Eisenerz, Leoben/. the radioactivity concentration of137Cs was two times higher than that of134Cs. Following concentration values were found:103Ru 0.1–63.0 nCi kg–1,134Cs 0.3–41.6 nCi kg–1, and137Cs 0.3–83.3 nCi kg–1. The activity of these nuclides decreased from July 1986 to September 1986.