As one of the early Korean Zen masters to settle in the United States, he opened many temples and practice groups across the globe.

Known by students for his many correspondences with them through letters, his utilization of dharma combat and expressions such as "only don't know" or "only go straight" in teachings, he was conferred the honorific title of Dae Jong Sa in June 2004 by the Jogye Order for a lifetime of achievements.

[1][2] Seung Sahn then performed a one-hundred day solitary retreat in the mountains of Korea, living on a diet of pine needles and rain water.

In the fall of 1948, Seung Sahn learned dharma combat while sitting a one-hundred day sesshin at Sudeoksa—where he was known to stir up mischief, nearly being expelled from the monastery.

[1][3][6] Coming to the United States in 1972, he settled in Providence, Rhode Island and worked at a laundromat as a repairman, spending much of his off time improving upon his English.

[7] The Kwan Um School of Zen was founded in 1983 and, unlike more traditional practice in Korea, Seungsahn allowed laypersons in the lineage to wear the robes of full monastics, upsetting some in the Jogye Order by allowing lay Dharma teachers to wear long robes.

He created the title Ji Do Poep Sa Nim (JDPSN) for those not ready for full dharma transmission but capable of teaching at a higher capacity.

He had been in and out of hospitals for heart complications for years preceding his death, and in 1987 began spending much less time at his residence in the Providence Zen Center.

[11] Seungsahn implemented the use of simple phraseology to convey his messages, delivered with charisma, which helped make the teachings easier to consume for Western followers.

This was another example of his skillful implementation of unorthodox teaching methods, adapting to the norms of Western culture and thus making himself more accessible to those he taught.

[9][14] Seungsahn also developed his own kōan study program for students of the Kwan Um School, known today as the "Twelve Gates".

Zen Master Seung Sahn has always told his students that the man with the cigarette is also very strong and that he will hit you if he doesn't approve of your response to his actions.

Seung Sahn died on November 30, 2004, at the age of 77 in Seoul, South Korea at Hwagaesa, the first temple where he served as abbot.

[23] Seung Sahn did two repentance ceremonies[citation needed] and the Kwan Um School of Zen has since developed an ethics policy that has guidelines for teacher/student relationships and consequences for unethical behavior.

[...] No one questions that Soen Sa Nim is a strong and inspiring teacher and missionary, wholly committed to spreading the Dharma, who has helped many people by his teachings and by his creation of institutions in which they can practice Zen.