Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in settled house dust and road dust samples collected from a core urban area of Hanoi. Levels of PAHs ranged from 830 to 3500 (median 2000) ng/g in house dust, and from 1400 to 4700 (median 1700) ng/g in road dust. Concentrations of PAHs in dust samples of this study were within the moderate range as compared with those from other countries in the world. Toxic equivalents to benzo[a]pyrene (BaP-EQs) in our samples ranged from 81 to 850 (median 330) ng BaP-EQ/g with principal contributors as BaP and dibenz[a,h]anthracene, which accounted for 69% to 93% of BaP-EQs. In almost all the samples, proportions of high-molecular-weight PAHs (HMW-PAHs with 4–6 rings) were higher than those of low-molecular-weight PAHs (LMW-PAHs with 2–3 rings), suggesting emission sources from combustion processes rather than direct contamination by petrogenic sources. Traffic activities were estimated as important sources of PAHs in the studied areas, for example, vehicular exhaust and tire debris.