 Park Hae-il began appearing in theatre productions ever since childhood, and he first established himself on stage rather than on the screen.In 2000 he was awarded the Best New Actor award in the theatre category of the Baeksang Arts Awards for his role in the play "Cheongchun-yechan" ("Ode to Youth").His film debut was in a minor role of Yim Soon-rye's "Waikiki Brothers", however he left a major impression in his second film "Jealousy Is My Middle Name", in which he played a conflicted young man who develops a fascination/hatred for his boss, who has stolen two women from him.