Exposing the Raduet Rn-Tn solid-state nuclear track detectors, radon (Rn: (222)Rn) and thoron (Tn: (220)Rn) activity concentrations have been measured in 7 kindergartens and 18 elementary schools in Slovenia. Diurnal variations of both gases were monitored using a Rad7 device. The Rn concentration was in the range from 145 to 794 Bq m(-3) in kindergartens and from 70 to 770 Bq m(-3) in schools, and the Tn concentration was in the range from 21 to 73 Bq m(-3) in kindergartens and from 4 to 91 Bq m(-3) in schools. The Tn versus Rn concentration ratio varied from 0.02 to 0.83. Monthly effective doses due to radon and its decay products ranged from 109 to 600 μSv month(-1) in kindergartens and from 21 to 232 μSv month(-1) in schools, and those due to thoron and its decay products ranged from 3.8 to 13.3 μSv month(-1) in kindergartens and from 0.29 to 6.62 μSv month(-1) in schools. The contribution of thoron to the total effective dose was from 1.3 to 11 % in kindergartens and from 0.4 to 17 % in schools.