Khairul started his football career with Pahang youth team in 1985. At that time he was only seventeen and he was the best youth goalkeeper for Pahang. His impressive performance with the Pahang youth team had attract him to represent Malaysia at the ASEAN School Championship at Jakarta, Indonesia. He was then chosen to be the part of Pahang FA senior squad during 1985 season.

In 1991, he was chosen to be the part of Malaysia national football team. His memorable games at the international arena are against England national football team where Malaysia lost 2–4 against the world giant. 1993 saw him clinch his first international title after helping Malaysia to defeat South Korea 3–1 at the 1993 Merdeka Tournament. During his time with the national team, Khairul said his feared player at the international arena is the Saudi Arabian forward Khalid al-Muwalid during the 1994 FIFA World Cup qualification (AFC). He also feared Alistair Edwards of Johor FA in the Malaysia League.

He also played for Malaysia national futsal team, and was in the squad that took part in the 1996 FIFA Futsal World Championship in Spain.

In 2002 and 2003 season he helped Sabah to their second and third finals. However, he again failed to help Sabah to clinch Malaysia Cup title after again losing to Selangor 1–0 in 2002 and 3–0 to Selangor MPPJ FC in 2003. Khairul was named the best goalkeeper in Southeast Asia in 1995. He officially retired from football during 2005 season after he failed to recover from an injury.

In 2013, he moves to Darul Takzim FC to become their new goalkeepers’ coach.