The Karen are by far the largest tribal group in Northern Thailand. While most Karen are Buddhist or animist, there is also a sizeable population that have readily embraced Christianity. This may be due in part to the many similarities between the Karen and Christian creation stories. In fact, it has been suggested that the Karen may be one of the lost tribes of Israel.

Although there is speculation as to where the Karen originated, they now regard Burma as their homeland. In recent history the Karen population in Thailand has grown significantly as many Karen seek refuge from the ongoing battle for independence and security in Burma.

The Karen culture encompasses a strong sense of harmony both with the environment and within their community, and their lives are governed by a strict moral code. Many of their festivals and ceremonies are acknowledgements of a communion with nature.

For the Karen, the distinction between forest and land for farming is blurred. When clearing land for farming, they do not practice total forest removal. Rather than using chemical pesticides and fertilisers, complementary crops are planted, and the traditional system of rotational farming allowed time for forest regeneration. Forests were managed so as to provide food, medicinal products and timber.

Most Karen villages also grow cotton plants, and the women are well known for their skills in weaving. The dress of Karen women is considerably less flamboyant than that of the other tribal groups and is made from cotton and natural dyes.

The Karen are the only tribe to have developed their own written language, using Burmese script.