Medicinal and aromatic plants (MAPs) have been grown and used extensively for health care and healing practices since time immemorial in Nepal. They possess cultural, religious and economic values in Nepalese communities. In recent years, the MAPs sector is a growing commercial sector in Nepal that provides livelihood opportunities for low income generating people especially in the Himalayas. In this regard, this study assesses the contribution of MAPs to the gross domestic product (GDP) of Karnali Province of Nepal. A total of 58 species of MAPs were identified in Karnali Province. It was found that various parts of these annuals, biennials and perennial plants have been used as medicines, perfumes and food. MAPs in Karnali Province generated economic output equivalent to NPR 160738 million (USD 1.39 billion) or 1.03% of GDP of Karnali Province and 0.02% of the National GDP in the fiscal year 2019/2020. However, the findings revealed that the current GDP estimate undervalues the contribution of the MAPs sector to the national GDP due to the non-inclusion of ethnobotanical uses of medicinal plants. Moreover, if all cash and environmental benefits people derive from this sector could be valued and recorded in the System of National Accounts, the GDP from MAPs would be much higher than the amount estimated in this study. We conclude that MAPs have a reasonable contribution to the GDP of Karnali Province and Nepal.