The level of radiofrequency electromagnetic fields (RF-EMF) exposure increases day by day as a natural consequence of technological development. In recent years, the increasing use of cellular systems due to technological developments in wireless communication systems has made it necessary to measure and evaluate RF-EMF originating from base stations which are the basic structure of these systems. In Turkey, as in April 2016, fourth generation of wireless mobile communication technology (4G) has been introduced and additional base stations are continuing to be added to the system. In this study, RF-EMF measurements were taken at four different times in order to examine and evaluate the change of RF-EMF before and after 4G in Atakum district which is one of the most crowded districts of Samsun, Turkey. Two of the measurements were taken before 4G and the remaining measurements were taken after 4G. Each measurement was taken at different times of the day (morning, noon and evening). The measurements were collected from 46 different locations using PMM 8053 RF-EMF meter which measures RF-EMF in the broad band from 100 kHz to 3 GHz. In the measurements, the maximum electric field strength (Emax) and the average electric field strength (Eavg) were recorded. The highest values that have been noticed in these measurements were 9.45 V/m and 17.53 V/m for Eavg and Emax, respectively. According to the measurement results, a decrease of 45.95% was observed in the measurement values of the morning hours compared to the measurement values of the evening and noon hours. The average RF-EMF value after 4G was introduced has increased by 30.95% compared to before 4G. Apart from these measurements, 24-hour measurements were taken at a location where the highest value was observed and analyzed to observe the change of RF-EMFs during a day.