A workshop was held from 28 February to 2 March 2006 at the National Institute of Standards and Technology (NIST) to evaluate the needs for new directions for complex matrix reference materials certified for radionuclide content, interlaboratory comparisons and performance evaluation (PE) programs. The workshop identified new radioanalytical metrology thrust areas needed for environmental, radiobioassay, emergency consequence management, and nuclear forensics, attribution, nonproliferation, and safeguards.