The analysis of airborne particulate matter (APM) by k(o)-NAA was assessed using: (1) BCR reference material (RM) simulated air-filters, (2) synthetic air-filters prepared by spiking blank filters with standard solutions, and (3) real APM filters. k(o)-INAA is a suitable technique for the analysis of APM, delivering accurate and precise results. However, the quality assessment of APM analysis appears to be a difficult task.