Traditional medicine using medicinal plants is an integral part of the culture and socio-economic well-being of people in northern Nigeria. Natural radioactivity is ubiquitous in all earth-born materials, including soil. The uptake of radionuclides by medicinal plants and the consumption of plants are the major pathways through which radionuclides find their way into the human body. Plant parts like the leaves, bark, roots, or extracts are often administered raw or as solutions without regulations. This has, thus, provoked concerns about the likelihood of human exposure due to the presence of primordial radionuclides in medicinal plants. Acknowledging the therapeutic values of medicinal plants requires the assessment of natural radioactivity levels to safeguard human health and ensure the quality of the medicinal plants. Hence, this study aims to establish radiological baseline data for medicinal plants in the Kano metropolis, Nigeria. Various types of medicinal plant samples were acquired from the Dawanau international grains market in Kano, and measurements of radioactivity were carried out using HPGe gamma-ray spectrometry. The average specific activities for 226Ra, 232Th, and 40K are found to be 43 ± 5, 37 ± 4, and 5883 ± 23 Bq/kg, respectively. The annual effective dose, total effective dose, excess lifetime cancer risk, and threshold consumption rates were determined. A comparison with similar studies conducted in other regions demonstrated relatively higher annual ingestion doses than most of the reported literature. However, these doses remain below the maximum ingestion dose of 290 μSv/y to avoid deleterious health effects, indicating that these medicinal plants are generally safe for consumption. Nevertheless, the potential effect of cumulative radiation doses should not be completely neglected, as medicinal plants constitute only a minor part of the total human diet. Therefore, the establishment of periodic monitoring and adherence to safe consumption thresholds are recommended to minimise the potential risks to as low as reasonably achievable. Public health awareness in the studied region through campaigns and school curricula is essential for public health safety.