The radon exhalation rate was measured in 32 soil samples collected from Hassan district of South Karnataka. Radon exhalation rate of soil samples was measured using can technique. The results show variation of radon exhalation rate with radium content of the soil samples. A strong correlation was observed between effective radium content and radon exhalation rate. In the present work, an attempt was made to assess the levels of radon in the environment of Hassan. Radon activities were found to vary from 2.25±0.55 to 270.85±19.16 Bq m−3 and effective radium contents vary from 12.06±2.98 to 1449.56±102.58 mBq kg−1. Surface exhalation rates of radon vary from 1.55±0.47 to 186.43±18.57 mBq m−2 h−1, and mass exhalation rates of radon vary from 0.312±0.07 to 37.46±2.65 mBq kg−1 h−1.