Ethnobotanical studies are useful in documenting, analyzing and communicating knowledge and interaction between biodiversity and human society. The objective of this study was to conduct ethnobotanical study and document medicinal plants and indigenous knowledge in Adi-Arkay woreda, North Gondar zone of Amhara National Regional State, Ethiopia. Ethnobotanical data was collected from April to September 2024 using semi-structured interview, focus group discussion, field observation and market survey. 105 randomly selected general informants and 16 key informants were participated. Descriptive statistics such as percentages and frequencies were used to data analysis. The prefence ranking, direct matrix ranking, fidelity level and informant consensus factor were computed to analyze data. A total of 101 medicinal plant species belonging to 90 genera and 51 families were collected and documented from the study area for the treatment of 79 different diseases of humans and livestock. Of these, 72 plant species (71.28%) were reported as remedies for human, 11 plant species (10.89%) as live-stock remedies, and 18 plant species (17.82%) for both human and livestock remedies. The family Fabaceae had the highest number of 7 species followed by Poaceae with 5 species. The leaves and roots were the most frequently used medicinal plant parts in the preparation of remedies, accounting for (41.54%) and (23.07%), respectively. The most methods of preparation of remedies were pounding, which accounted for (19.59%) of the 194 remedy preparations, followed by crushing (13.92%) then squeezing (11.34%). Oral application was the most commonly (56.19%) used route of application followed by dermal (30.41%). The highest informant consensus factor value for human ailements was observed for stomachache, gastritis & parasite (0.68) and pumping, bloating, diaharrea, bloating and stomachache diseases observed (0.78) for livestock ailements. The highest fidelity level index was (98%) for Allium sativum species; for the treatment of cough. In preference ranking, Linum usitatissimum and Zingiber officinale, were ranked first and second, to treat stomachache for human ailements. Also, Rhamnus prinoides ranked the first to treat pumping for livestock ailements. The direct matrix result showed that Eucalyptus globulus, Juniperus procera, and Acacia abyssinica ranked from first, second and third, respectively in terms of their multiple use. The major way of transfer of indigenous knowledge on medicinal plants was orally to a family member, especially to an elder son. The major threats of medicinal plants are agricultural expansion followed by firewood and charcoal