Realizing the importance of herbal medicine, it is essential to investigate radioactivity in medicinal plants in order to protect human health, ensure the quality of herbal medicines, and so on. The present study determines the concentration of naturally occurring radioactive materials in 21 medicinal plants collected from different areas of Chattogram district, Bangladesh using High Purity Germanium (HPGe) gamma-ray spectrometry. The activity concentrations of 226Ra, 232Th and 40K were found to range from less than MDA to 19.05 ± 2.90 Bqkg−1, 4.50 ± 2.77 to 29.55 ± 9.22 Bqkg−1, and 68.89 ± 14.47 Bqkg-1 to 241.67 ± 48.43 Bqkg−1 respectively with the corresponding average values of 16.46 ± 5.11 Bqkg−1, 15.73 ± 3.90 Bqkg−1 and 157.93 ± 59.84 Bqkg−1. Based on the consumption characteristics, the Average Annual Committed Effective Dose (AACED) for the identified radionuclides was calculated and found as 4.39E-04 mSv/y, 3.62E-03 mSv/y, and 6.99E-04 mSv/y, respectively with average of total AACED as 4.76 E-03 mSv/y. The AACED due to ingestion of the natural radionuclides in the medicinal plant samples is far below the world’s average annual committed effective dose of 0.29 mSv/y as per the UNSCEAR Report 2008. Therefore, the medicinal plants collected from this region are safe for human consumption. This work may provide baseline data on radioactivity in medicinal plants, which could be useful for any future research on the safety of radiation exposure to humans from medicinal plants and herbs.