In Kenya, traditional knowledge on herbal medicine has remained a mainstream source of maintaining wellbeing for generations in many communities. However, the knowledge has been eroded in the course of time due to sociocultural dynamics virtually advanced by Christianity and formal education especially in the Kikuyu community. The study documented current ethnobotanical knowledge and threat to the traditional knowledge on medicinal plants among the Kikuyu community. A survey was carried out in Mathira, Tetu, Kieni, Othaya, Mukurweini, and Nyeri Town constituencies. Thirty practicing herbalists were purposively sampled; 5 per constituency. Data was obtained through semi - structured questionnaires and analyzed both qualitatively and quantitatively. A total of 80 ailments treated using 111 medicinal plant species distributed within 98 genera and 56 families were documented. Prevalent communicable diseases treated using herbal medicine included; gonorrhea (17.5%), malaria (15%), respiratory infections (12%), colds (10%) and amoebiasis (10%). Non-communicable diseases were; joint pains (11.1%), ulcers/hyperacidity (8.7%), high blood pressure (8.7%), intestinal worms (11.1%) and arthritis/gout (10%). Frequently harvested plant materials were; roots, barks and leaves. The study concluded that, traditional medicine practitioners in Nyeri County possessed wide knowledge of herbal medicine but this knowledge was on the verge of disappearing as it was largely a preserve of the aged generation. The study recommended massive campaign about the benefits of using herbal medicine in the study area. Further pharmacological studies are recommended on the mentioned plant species aimed at establishing their efficacy and safety as well as standardization as potential drugs.