Shin auditioned in America through Brothers Entertainment and was the first member to be placed into Shinhwa. He officially debuted as part of Shinhwa on March 24, 1998 with a performance of their first single "해결사" (The Solver) on KM Music Tank. Since then, he has released ten Korean and one Japanese studio albums with Shinhwa.
Shin debuted as a solo artist in 2005 with the release of his solo album entitled Love of May (오월지련, 五月之戀) in 2005. This album ranked number one on the HMV pre-order sales chart in Japan in February 2005, with 180,000 copies sold. Shin released his second album, entitled The Beginning, New Days on August 8, 2007. His song, "First Person", was #1 on the K-pop Top 10 chart. His album sold 30,000 copies on its first day of release and 50,000 copies in a week.
He has since released five Korean and two Japanese studio albums.
In June 2011, after releasing his fifth Korean studio album, The Road Not Taken, Shin wrapped up a series of performances in Seoul, Busan, and Shanghai. He also hosted a special two-day, 2011 Tour in Seoul - The Road Not Taken Act II, at Kyung Hee University on September 3 and 4. Then in July, he recorded a duet "I Believe," with Shunsuke Kiyokiba former member of Exile.
In March 2012, Shin reunited with his Shinhwa band mates for their comeback after four years, under the management of 'Shinhwa Company'. It is a joint venture agency for members to perform as a group, of which Eric and Lee Min-woo are co-CEOs and the remaining members are shareholders. The Company manages the group as a whole, whilst members' individual activities are managed by their respective agencies. The group released their tenth studio album The Return on March 23, 2012, launched their comeback concerts 2012 Shinhwa Grand Tour: The Return throughout Asia and their first exclusive variety program Shinhwa Broadcast premiered on March 17, 2012 on cable channel JTBC.
On March 25, during the encore performance of the 2012 Shinhwa Grand Tour in Seoul: The Return, Shin injured his knee. At the start of the performance of "Yo!", he was shot up on stage but did not land safely. He ruptured his cruciate ligament and severely damaged the cartilage and ligament surrounding the meniscus, requiring surgery and six months of rest. Shin had previously ruptured his cruciate ligament again, an injury previously sustained during a concert in 2001, and had corrective surgery on his left knee but the cruciate ligament in his right knee continued to suffer damage, for which he was exempt from mandatory military service. However, he has put off surgery, but has continued treatment through the end of promotional activities for Shinhwa's tenth studio album, The Return. He performed by singing in a chair for their first music show comeback on March 29 on M! Countdown, where they performed "Venus" and "Hurt".
In September Shin along with band-mate Lee Min-woo performed at the West Bank Music Festival in Shanghai from September 30 to October 2, as K-Pop representatives along with other international artists such as Michael Bolton in front of an audience of 100,000 people.