Background: Ondo city in Ondo State Nigeria includes Ondo East and West could be described as a research city due to antecedent number of research institutes. Materials and Methods: Dose due to radioactivity content of soil samples from sixteen waste dump sites in Ondo, Southwestern Nigeria was determined using gamma-ray spectrometer in order to evaluate the radiation hazard health profile and excess lifetime cancer risk ELCR. Results: The weighted average value of radon emanation coefficient, mass exhalation rate, concentration in soil gas and surface exhalation rate were 10.5%, 15.2 µBq kg^-1 s^-1, 2.2 kBq m^-3 and 18.8 mBq m^-1s^-1. The weighted mean concentrations obtained were 354 ± 53, 58±14 and 23 ± 2Bq kg^-1 for ⁴⁰K, ²²⁶Ra and ²³²Th respectively. Radium equivalent activity (119.11Bq kg^-1), Outdoor external dose (54.26 nGy h^-1), Indoor external dose (107.04 nGy h^-1), and total average annual effective dose (0.59 mSv y^-1) were obtained. From the measured γ-rays spectra, elemental concentrations were determined for ²³²Th (mean 5.8ppm), ²²⁶Ra (mean 4.8ppm) and ⁴⁰K (mean 1.1 %). Thorium was lower than world average 7.4ppm by a factor of 1.3; radium was higher than the world average (2.8 ppm) by factor 1.7 while potassium was relatively equal to world average (1.3 %). Conclusion: The total excess lifetime cancer risk ELCR was found to be 1.95 x 10^-3 which was slightly higher than the world average. In addition, a good correlation was found between the radium concentration and radon exhalation rate in the area.