Environmental radiations exist everywhere and each natural substance contains trace amount of radioactive material. Radon alone contributes about 55% of total environmental radiations. Effects of these radiations on humans were firstly reported by Agricola for miners in the Erz Mountains of Eastern Europe in 1556 and in 1879 first association of lung cancer with miners were established. Nowadays indoor radon is believed to be second leading cause of lung cancer after smoking. Keeping in view the importance of subject indoor radon survey has been conducted in district Kotli of Azad Kashmir (Pakistan) using CN-85 based box type radon detectors. In this regard, 120 radon box type detectors were installed in a bedroom and living room of each house. The detectors were retrieved after exposing to the indoor radon for a period of 3 months and were etched in 6 N NaOH solution at 70^oC for 3 hours. The observed track densities were then related to the indoor radon concentration. Arithmetic and geometric means were found to be 84±6 Bq. m^-3, 73±6 Bq. m^-3 and 80±6 Bq. m^-3, 71±7 Bq. m^-3 in the living rooms and bedrooms, respectively. For bed rooms indoor radon concentration varied from 38±9 to 107±5 Bq. m^-3 whilst for living rooms 52±8 to 263±3 Bq. m^-3. The overall mean value of the indoor radon concentration in the studied area was found to be 77±7 Bq. m^-3. According to the recommendations made by the Health Protection Agency, UK (200 Bq. m^-3), all the houses surveyed have the indoor radon concentration within the safe limits.