On October 14, 2009, the group released their debut single album, Just BLAQ, which topped various online and offline music charts in South Korea.

They performed various songs from their produced EP, Just BLAQ and were met with praise, with many spectators at the concert and fans considering them as the next DBSK.

[7] Coinciding with the music video, MBLAQ's debut single album "Just BLAQ", was released on the same day,[8] topping various charts in South Korea.

[11] Thunder also stated that he only joined MBLAQ fifteen days prior to their debut, and that while he sang and rapped live for their performances, his voice is not actually featured on any of the recorded tracks for Just BLAQ due to time constraints.

[15] On December 29, 2010, MBLAQ released a teaser music video, featuring their song "Cry", for their upcoming full-length album, BLAQ Style.

[17] MBLAQ participated in the production of BLAQ Style,[18] with Seungho composing and playing the piano for the introductory track "Sad Memories" and Mir writing the rap lyrics for "You're my +".

[30] MBLAQ released their Japanese album on May 4, 2011, with live performances held at Osaka, Sapporo, Nagoya, Fukuoka, and Tokyo.

[32] On May 3, MBLAQ kicked off their Japanese promotions with their debut event held at Kanagawa Lazona Kawasaki Plaza, gathering a reported 10,000 fans.

[37][38][39] On July 15, when Mona Lisa was released in stores, it reached number one on the Hanteo Real-time, Daily and Weekly Charts.

[44][45] As part of their promotions, MBLAQ travelled to Nagoya, Japan on October 28, Osaka on the 29th, and Tokyo on the 30th to celebrate the release of their new single.

On October 30, 1,500 fans were chosen by a lottery among the 12,500 people who gathered at the venue to join the LIVE performance and Great Bingo Tournament.

[48] On January 1, 2012, a video teaser for MBLAQ's fourth extended play album was released, including their secondary single, “낙서 (Scribble)”.

The teaser ends with the members standing center stage with a string orchestra gathered on either side of them, shooting at the audience and finishes with a violent blood splatter that reveals their lead single's name, "전쟁이야 (This is War)".

Lee Joon reprised his role as the recurring lead image of MBLAQ in the music video as a deadly but warm-hearted assassin.

was released on the same day as the music video, containing a total of five songs: "Run", "전쟁이야 (This is War)", “낙서 (Scribble)”, "아찔한 그녀 (She's Breathtaking)", and "Hello My Ex" respectively.

Tune Camp's official YouTube channel on August 12, showing the photoshoot, composing and preparation for Love Beat.

On March 24, 2014, the music video of Be a Man was uploaded and the album which consists of seven tracks which the members actively participated in the writing and composing part,[60] was subsequently released online at 12PM (KST).

Tune Camp released an official announcement stating that this was a rumor and that both Joon and Thunder are in talks with the company regarding their future activities.

[69] With Rain being their mentor and major influence, he has either written, composed, produced and/or choreographed a few tracks for MBLAQ, including "Oh Yeah", "G.O.O.D Luv", and "Y".

Countdown, Joon also took on the role of MC for QTV's Ranking Women,[79] however he has since left the program to focus on his music activities.

The members of MBLAQ made an appearance in Lee Joon's drama Housewife Kim Kwang Ja's Third Activities.

In March, MBLAQ took part in Mnet Wide's new corner, Refreshing Interview, with their own show called Sesame Player.

[85] In August, members Lee Joon and Thunder have collaborated with Chinese artist Vision Wei, and their digital single "Run Away" was released on the 25th.

[89] On January 26, MBLAQ performed at a special concert MBC Music Era (I Giorni Della Musica) held in Ilsan.

On February 10, MBLAQ's Lee Joon & Mir release a digital single Do You Remember with legendary singer Kim Jo Han.

On March 15, it was announced that MBLAQ would be making a cameo on the drama The Strongest K-Pop Survival, which stars member Mir's sister, Go Eun Ah.

In April it was confirmed that Lee Joon would have a role in the KBS2 TV drama I Need a Fairy with fellow idol star Go Woori of Rainbow.

In January, it was confirmed that Thunder will star in MBC trendy drama Nail Shop Paris as the lead opposite to KARA's Gyuri.

[95] It was reported that MBLAQ will participate in 64th Sapporo Snow Festival in Japan to promote Korean pop culture, the charity concert will take place on February 9.

[96] In February, G.O was confirmed to have a cameo role in upcoming KBS2 sitcom Remaining Love along with KARA's Seungyeon, ZE:A's Siwan, SECRET's Ji Eun, and INFINITE's Sunggyu.