The survey of medicinal plants together with their uses, frequency of application, and the way of preparation within the Agta communities of Aggugadan, Bugatay, and Lapi in Peñablanca, Cagayan, Northern Philippines was the main concern of this study. Agtas served as the respondents due to their broad knowledge base in herbal medicine and well-preserved tradition. Specifically, the study aimed to determine: (1) the medicinal plants available in the three Agta communities of Peñablanca, Cagayan; (2) the medicinal plants which contain curative ability to the corresponding ailments of the Agtas; and (3) the practical procedures which are involved in the preparation on the use of medicinal plants that ensure desired individual therapeutic eﬀect. The collection of the specimen was made easier by the use of a semi-structured questionnaire and focus group discussion accomplished by the researchers. The specimens collected were compiled in a herbarium and the collected plant samples were sent to the Botany Division of the National Museum and the Research Division of the Regional Office of the Department of Environment and Natural Resources. The said institutions classified the plant samples taxonomically. Necessary information gathered and a listing of plants with actual photos, common names, indications, frequency of use were produced. Findings of the study showed that most of the collected plants were uncommon.