Song Ji-hyo as Oh Jin-hee, intern
Choi Jin-hyuk as Oh Chang-min, intern
Lee Pil-mo as Gook Cheon-soo, attending physician of Emergency Medicine
Choi Yeo-jin as Shim Ji-hye, assistant professor of surgery
Clara – Han Ah-reum, intern
Supporting characters
Yoon Jong-hoon as Im Yong-gyu, intern
Im Hyun-sung as Park Sang-hyuk, intern and Young-ae’s husband
Chun Min-hee as Lee Young-ae, intern and Sang-hyuk’s wife
Choi Beom-ho as Go Joong-hoon, chief of Emergency Medicine
Park Sung-geun as Ahn Young-pil, surgeon
Heo Jae-ho as Jang Dae-il, third year resident
Kwon Min as Kim Min-ki, first year resident
Kim Hyun-sook as Choi Mi-jung, ER head nurse
Lee Sun-ah as Heo Young-ji, ER nurse
Choi Yu-ra as Son Ye-seul, ER nurse
Lee Mi-young as Jo Yang-ja, Jin-hee’s mother
Jeon Soo-jin as Oh Jin-ae, Jin-hee’s younger sister
Park Doo-sik as Kim Kwang-soo, indie singer and Jin-ae’s husband
Park Joon-geum as Yoon Sung-sook, Chang-min’s mother
Kang Shin-il as Oh
