Since long time ago, humans have used medicinal plants. Currently, many of the contemporary drugs can be traced to plant origins. Human activities such as deforestation and farming risk the availability of medicinal plants of medical importance; therefore, there is a need to document knowledge and information on these plants. Structured questionnaires, which involved oral interviews and discussions, were used to gather information from the 35 selected herbalists. The information on every medicinal plant used in the treatment of human diseases was documented. A total of 26 medicinal plants were recorded with trees (38.5%), herbs (30.8%), shrubs (26.9%), and climbers (3.8%). The plant parts were either used singly or in combination. The mixture of leaves, roots, and barks were the most preferred combination by 77.1%, followed by barks and roots by 57.1%, and leaves and barks by 11.4%. The diseases treated were gastrointestinal ailments by 97.1%, while skin and respiratory were 80% each. Boiling was the most preferred method of preparation (58%), followed by burning to ashes (28%), boiling (12%), and raw (2%). Oral administration was the most preferred method (63%), followed by swabs (24%), and inhalation (13%). The medicinal plant's primary source was Cherangani forest (91.4%), although some herbalists had also domesticated some medicinal plants (8.6%). The study provides information on medicinal plants used by herbalists in the Marakwet community, which be used in investigating potential active compounds in the documented medicinal plants for the development of crude drugs.