This study investigates storytelling knowledge and functions embodied in different ethnic folktales and seeks to identify ethnic secondary students' attitudes towards storytelling using a picture series. Fifteen folktales were collected from storytellers belonging to four ethnic groups in Chiang Khong District, Chiang Rai Province, Thailand. One Hmong story, adapted into a lesson using a picture series, was used to instruct 11 Hmong secondary students. Afterwards, these students reflected on their learning through the picture series by responding to a set of questionnaires and open-response questions. The data were then analyzed using a story-analysis framework, descriptive statistics, and content analysis techniques. Findings revealed that the content found in the ethnic folktales can be categorized into six major typologies: gods and goddesses, parental gratitude, love and family, magic spells and ghosts, life and destiny, and animals. These stories were divided into two primary groups. The first group consists of eight stories with multiple types of knowledge and two functions. The second group contains seven stories with a single type of knowledge and two functions. The stories with multiple types of knowledge and two functions contain moral lessons intended to promote positive actions and behavioral changes. Additionally, the results revealed that the students surveyed held positive attitudes towards using a picture series for their learning through storytelling. They perceived that picture series can reinforce language and cultural learning, develop analytical thinking skills, and increase storytelling abilities. Therefore, this study shows that Hmong students can use their local stories as a way to learn English and understand cultural values, beliefs, identities, and ideologies when communicating with others.