Indoor dust samples were collected in the summer of 2017 from 10 residential buildings, 7 commercial buildings and 7 official buildings of Bushehr. Sixteen polycyclic aromatic hydrocarbons (PAHs) were analyzed by GC–MS. The sum concentration of the 16 PAHs in dust spanned between 87.8 to 14619 mgkg-1d.w. with a mean of 2211.6 mgkg-1d.w. The mean concentration of PAHs for the dust samples from the commercial buildings was higher than from residential buildings and, from residential building was higher than from official buildings. The cancer risk through dermal and ingestion route ranged from 10-6 to 10-5 across all the dust samples, while the average of cancer risk through inhalation pathway was 10-9 to 10−12, about 104 to 106 times lower, when compared with other two pathways (ingestion and dermal contact). Also, the level of cancer risk for children was significantly higher than the corresponding risk for adults. The results of this work would be suitable to enhance the quality of living environment and human health in Bushehr province.