The aim of this study is to determine the relationship of radon concentrations between dwellings and the schools located in the same regions and to obtain related indoor average radon concentration dwelling-school correction factor for similar locations. The research has been carried out by determining indoor radon concentrations at schools and dwellings located at the same districts in the selected two separate research fields called The Former Adapazari region and The New Adapazari region in the city of Adapazari using a total of 81 Cr-39 passive radon detectors for 75 days. The average radon concentrations have been determined for the dwellings and the schools in 15 districts of the Former Adapazari region as 59.9Bqm -3 and 57.1Bqm -3, respectively. The results in 4 districts of the New Adapazari region were 63.5Bqm -3 for the dwellings and 61.0Bqm -3 for the schools. Moreover, the annual effective doses were calculated as 1.33mSv/y and 1.41mSv/y for the dwellings of Former Adapazari and New Adapazari, respectively. It was seen that the doses received in the dwellings are about four times the doses received in the schools. The indoor radon concentration dwelling-school correction factor was found to be 1.04±0.01 for the research area. © 2011 Elsevier Ltd.