Introduction Foodstuffs are known to contain natural and artificial radionuclides. Determination of radionuclide concentration is of great significance for the protection of human health. The main objective of the present study was the quantification of radionuclides in tea samples, cultivated in Guilan Province in North of Iran. Materials and Methods The activity concentrations of 226Ra, 232Th, 40K, and 137Cs in 18 tea samples were measured, using a gamma spectrometry system. In addition, radium equivalent index (Raeq) and radiation hazard index (HI) were calculated. ANOVA test was used for the statistical analysis of the data Results The concentration of 137Cs was below the minimum detectable activity (MDA). The concentrations of 226Ra and 232Th ranged from < MDA to 0.042 and < MDA to 0.037  Bq/kg respectively. The mean concentration of 40K was 410±15  Bq/kg. Based on the findings, the concentration of 40K was significantly higher than other radionuclides (P