Main •
Joo Won as Kim Tae-hyun •
Jung Yoon-seok as young Tae-hyun :A skilled surgeon, who under the alias Yong-pal moonlights as a mercenary doctor for hire. He falls in love with Yeo-jin. •
Kim Tae-hee as Han Yeo-jin :A chaebol heiress placed in a coma by her enemies to get their revenge. She falls in love with Tae-hyun. •
Jo Hyun-jae as Han Do-joon :Han Yeo-jin's half-brother, who covets his sister's inheritance. •
Chae Jung-an as Lee Chae-young :Han Do-joon's wife.
Supporting •
Jung Woong-in as Chief Lee Ho-joon •
Stephanie Lee as Cynthia Park • Song Kyung-chul as Doo-chul •
Min Jin-Woong as Lee Sang-Chul •
Ahn Se-ha as Man-sik •
Bae Hae-sun as Nurse Hwang •
Im Kang-sung as Cha Sae-hoon • Jo Bok-rae as Park Tae-yong • Cha Soon-bae as Chief Shin •
Kim Mi-kyung as Kang Soo-min, Charge nurse, surgery •
Oh Na-ra as Charge nurse, intensive care • Park Pal-young as Hospital director •
Park Hye-su as Kim So-hyun • Choi Joon-Yong as Tae-hyun's father •
Kim Na-woon as Tae-hyun's mother •
Nam Myeong-ryeol as Chae-young's father •
Jang Gwang as Chairman Go • Yoo Seung-mok as Detective Lee Hyung-sa • Jo Hwi as Detective Kim •
Choi Min as Choi Sung-hoon (
guest)
Special appearances •
Lim Hwa-young as Han Song-yi •
Kim Jae-young as Yong Pal 2 (ep.18) == Original soundtrack ==