In 2003, he started his coaching career with
Lahti Pelicans U20 team, and became head coach of their senior team in the following year. The team was not competitive and they ended last of 13 teams that year. He then became assistant coach of
Blues in 2005 and spent two years as an assistant before being promoted as head coach in 2007. He was awarded
Kalevi Numminen trophy in 2008 and 2010 after Blues got silver medals. In 2010, he was chosen as an assistant coach of Finnish national team. The season 2011–2012 Matikainen coached
HIFK Helsinki. In summer 2012 he signed a tree year contract to Avangard Omsk (KHL). In 2014 he signed a one-year contract to
HC Slovan Bratislava (KHL). In the spring 2015 he signed a tree year contract to Lahti Pelicans. Petri Matikainen moved to Austria to coaching
EC KAC in 2018. Klagenfurter AC led by Matikainen, has won the
Austrian League championship for the second time in a row. In June 2023, EHC Biel announced him as their new coach for the
2023–24 season. He was fired in his first season with the team in February 2024, following bad results and complaints from the players about his coaching methods, attitude and lack of communication. In March 2025, Matikainen returned to his native Finland, signing a contract for the remainder of the
2024–25 Liiga season with
Oulun Kärpät. His tenure with Kärpät ultimately lasted only twelve days, consisting of five games, as the team failed to make the playoffs. Matikainen was appointed as the head coach of
JYP Jyväskylä for the 2025–26 Liiga season after signing a one-year contract with the team. ==Career statistics==