Abstract Using high-resolution gamma-ray spectroscopy, the terrestrial gamma radiation in all the predominant types of geological rock formations appearing in Cyprus was measured. Soil samples were collected from each rock type, sealed in 1 l plastic Marinelli beakers, and measured in the laboratory for 24 h each. From the measured gamma-ray spectra, activity concentrations were determined for 232 Th (range from 1.3 to 52.8 Bq kg −1 ), 238 U (from 0.9 to 90.3 Bq kg −1 ) and 40 K (from 13 to 894 Bq kg −1 ). Elemental concentrations mean values of (2.8±0.7) ppm , (1.3±0.3) ppm and (0.6±0.1)% were extracted, for thorium, uranium and potassium, respectively. Absorbed dose rates in air outdoors were calculated to be in the range of 0.1– 50 nGy h −1 , depending on the geological features, with an overall mean value of (14.7±7.3) nGy h −1 . The corresponding effective dose rates per person outdoors were estimated to be between 0.1 and 61.4 μSv yr −1 , assuming a 20% occupancy factor.