Materials from decommissioning of nuclear facilities can be re-used without restrictions, if their mass specific activities are in accordance to the guidelines for allowable concentrations. To determine the nuclide specific activity level of representative samples, a clearance laboratory was installed at the Research Center Karlsruhe. For the purpose of low level radionuclide analysis, procedures, developed for environmental monitoring, were successfully adapted to decommissioning materials. For radionuclides, for which adequate procedures were not available, new methods were developed. The procedures for the analysis of radionuclides of prior interest for decommissioning measures are outlined, together with the respective sample decomposition methods.