The public voted him number one, while his songs gained airplay. Shortly after, he was booked by Sony BMG Russia to release an English album in all the ex-soviet countries in 2008, although this never materialized and his collaboration with the Russian branch was terminated. Seeing his growing popularity, ERT asked him to compete in the Greek national final for the Eurovision Song Contest 2008.
2008: Greece's Eurovision national final
Main article: Greece in the Eurovision Song Contest 2008
Kostas Martakis in Moscow where he releases his Russian song ("Always and Forever").
Kostas Martakis competed in the Greek National Final with a song by Dimitris Kontopoulos, with lyrics by Vicky Gerothodorou. The song was "Always and Forever". and it was recorded in two different styles.
The pop rock version of the song was originally supposed to be performed at the National Final, but the dance version was chosen instead by Martakis and his label.The winning entrant was "Secret Combination" by Kalomoira, and Martakis' entry "Always and Forever" placed second. Following the Greek national final, a Russian language cover of "Always and Forever" based on the dance version with the title (With you forever) was released in ex-soviet countries. In December 2008, "Always & Forever" was added to American retailer Abercrombie & Fitch's nationwide US in-store music playlist, thus introducing the song to the American market.
Kostas Martakis and Danish-Greek singer Shaya were chosen to record a Greek-language version of Right Here, Right Now from the soundtrack of the Disney film High School Musical 3: Senior Year. The cover was titled "Mikroi Theoi" (Little Gods) and was released as a single off of the Greek edition of the film's soundtrack, as well as being made into a music video with Martakis and Shaya molded together with scenes from the film. The music video was included as a bonus feature on the Greek edition of the film's home video release. Walt Disney Records, via its international distribution partner EMI, commissioned several local market, foreign language versions of songs from the entire High School Musical series, although "Mikroi Theoi" was the only Greek version song.
"Fila Me" is another single by Martakis of which was made into a music video and released as a digital single. Martakis then took a break from recording and live shows as he was called to fulfill service in the Hellenic Navy.
In fall 2008, Kostas Martakis was the opening act for the Athens concert of Jennifer Lopez. He was chosen by concert organizers after they reviewed several video screenings of Greek artists. Ιn November 2008 American television station E! included Martakis on their "25 Most Sexy Men in the World", describing him a "Greek God"
2009 _ present: Second album Pio Konta
In March 2009, it was announced that Kostas Martakis signed with Universal Music Greece. The successful collaboration with Sony BMG launched his debut album and helped spawn nine singles, a notable achievement for a new artist in the Greek music industry, and his departure was on good terms.
In June 2009, Martakis released a song as a digital download single titled "Pio Konta" (Come closer) composed by Swedish producers Holter & Erixson. A music video, directed by Dimitris Silvestros, debuted shortly after, while the song received a fair amount of airplay. Martakis released his second album Pio Konta on November 12, 2009.
2011: Record "Sex Indigo", in a study in Moscow with Russian pop star Diana Díez.Tambien participated in the second season of Dancing with the Stars with Maria Antimisari. The final of Dancing with the Stars was on June 12, where Kostas Martakis won second place.
2012: Lanzo his third studio album entitled Entasi (intensity)
In theater Veaki, Kostas made his acting debut in the musical Rent. Here plays decadent rock star Roger Davis and comes to us on stage telling the story of a group of marginalized young people, trying to survive in New York in the 90s.
Also recorded the Greek version of the summer hit Mommy Claydee Good.
2013: In his official Facebook page announced the launch of their another single "Ta Ta Kalokairina Sagapo".