Main Cast:
* Kwon Sang-woo as Park Tae-shin (Cardiothoracic Surgeon)
* Jung Ryeo-won as Seo Joo-young (Cardiothoracic Surgeon)
* Joo Ji-hoon as Kim Tae-shik (Neurosurgeon)
* Oh Yeon-seo as Ahn Joo-young (Cardiothoracic Surgeon)
* Lee Hee-joon as Han Seung-jae (Cardiothoracic Surgeon)
* Choi Minho as Kim Sung-woo (Cardiothoracic Surgeon)
Supporting Cast:
* Kwak Do-won as Joong-sik
* Kim Ki-bang as Han Yi-chan (Cardiothoracic Surgeon)
* Jang Seo-kyung as Kang Hye-soo
* Yoon Joo-hee as Chae Young-eun (Cardiothoracic Surgeon)
* Lee Seo-jin as Lee Joo-hyun
* Kim Young-kwang as Lee Sung-jae
* Jo Jae-yoon as Kang Ho-jun
* Jung Woong-in as Park Min-woo (Head of Cardiovascular Department)
* Lee Ki-woo as Yoo Jae-hyun (Cardiothoracic Surgeon)
* Lee El as Park Eun-seo
* Kim Yong-gun as Chairman
Note: This list includes the major actors and actresses, but there were many other supporting roles in the drama.