Debut Eunhyuk with Super Junior

2005-2006: Debut Eunhyuk with Super Junior

Eunhyuk is also a lyricist and wrote the rap lyrics for a majority of Super Junior's songs. The rap lyrics to "Show Me Your Love" from the winter single with TVXQ was written by him, along with Heechul and Shindong, and "One Love". "여행" (A Short Journey) from repackaged version of Bonamana was written by him and composed by Donghae. Along with Shindong and Donghae, he also choreographs some of Super Junior's dance routines.

2006-2010: MC and sub-groups

Eunhyuk was partnered with band mate Leeteuk as radio DJs for KBS Super Junior's Kiss The Radio (aka SUKIRA) from 21 August 2006. With the exception of fours months from March to June 2011, where band mate Yesung temporarily replaced Eunhyuk, while he was away on promotional activities for Super Junior-M's third EP Perfection.

Eunhyuk replaced Kangin as MC on Mnet's music programme M! Countdown in late 2006. He hosted with band mates Leeteuk and Shindong until early 2008. In February 2007, he was placed in the trot-singing sub group Super Junior-T. A year later, he became a member of Super Junior-Happy.

From 2009, Eunhyuk, along with Leeteuk and Shindong, has been regular guests SBS's Strong Heart. Where they host special segment, Boom Academy. He is also frequent guest on Star King, also on SBS, with fellow Super Junior members.

On 26 February 2010, Eunhyuk was diagnosed with H1N1 influenza, but was set to appear as a guest at label mate Girls' Generation's Into the New World encore concert in Seoul, hence has to pulled out and was replaced by band mates Leeteuk and Heechul.