Since the existence of the world, human beings have been exposed to natural radiation. Determining the natural radiation level and the radiological parameters is very important in terms of determining the amount of radiation people will be exposed to. Since the population of Istanbul is very high, the number of people that will be affected by the radiation level there is high. In this study, it was aimed to determine the natural radiation level and radiological parameters in Cekmekoy district of Istanbul. For this, natural radionuclides were measured with gamma spectroscopy system based on NaI(Tl) detector for 17 soil samples collected from Cekmekoy-Istanbul. As a result of this study, the mean activity concentrations of (40) K, Ra-226, and Th-232 obtained as a result of the measurements were found to be 449 +/- 9, 29 +/- 1, and 28 +/- 1 Bqkg(-1), respectively. Mean absorbed dose rate (D-R) and excess lifetime cancer risk (ELCR) were calculated as 49 nGyh(-1) and 0.21 x 10(-3), respectively. Basic statistics were performed to determine the relationship between the activity concentrations of radionuclides and radiological parameters. In conclusion, mean natural radioactivity and radiological parameter levels are calculated lower than the world average.