Food plants used by Hmong from six villages in Mae Rim district, Chiang Mai province,Thailand, were studied during March 2012 to February 2013. Eight informants were interviewed individually in the field and information was verified for three times. One hundred and thirty species documented belongs to 58 families and 105 genera. Two threatened plants in Thailand: Elsholtzia penduliflora and Lilium primulinum var. burmanicum, using as vegetable and dessert respectively, were among the list of Hmong food plants. A kind of soup using vegetables and several culinary herbs boiled with chicken was a popular Hmong diet and some specific plants with volatile oils were normally used in the soup ingredients, e.g. Acorus gramineus, Artemisia lactiflora, Artemisia sp.1and E. penduliflora. The Hmong believes that this food is a superior tonic to restore strength for farmers. Further study on nutritional properties could reveal potential usefulness of the plants used, indicate value of traditional botanical knowledge and urge for conservation of the plant resources and local wisdom, which will be critical for food security of the communities in the future.