ABSTRACT. -Heavy metals content in PM 10 samples at two urban Romanian sites. Aerosol particles were traditionally investigated in Romania for their metal content in extremely polluted areas (critical polluted areas) like CopsaMica or Baia Mare, because of their negative effects on water, soil and vegetation in their surrounding regions. However, combustion of fossil fuels, metal production and waste incineration, main sources of toxic metals such as Cd, Pb, Ni, might be also located nearby of other cities. Therefore, even here the population can be exposed to the potential harmful effects of these toxic metals and the air quality can be seriously affected if high concentrations are attained. Present work assesses concentrations, variability, and compliance with the EU regulations of the trace metals Ni, Cd, Pb levels in PM 10 samples in two Romanian cities, Iasi and Cluj, at urban background and traffic stations. The cities have a medium size but because of their rapid development both cities play an important regional role. They also present different topographies and different climatic characteristics. Data were extracted from European AQ database AirBase for the period 2009-2012. Measurements of PM 10 and PM 2.5 are obtained by gravimetric analysis and those of heavy metals (Pb, Cd, Ni) by atomic absorption spectrometry. Data sets are acquired through measurements made on a daily average basis. Measurement annual and seasonal summary statistics were performed and analyzed for all data during