Augustinussen started his career with
AaB. Due to his height of 192 cm and good speed, Augustinussen played his first years as a striker. He made his
Danish Superliga debut for AaB in April 2000. He was a successful striker in his youth years, but had difficulty finding his goalscoring form as a senior. As he only managed to score 11 goals in his first three-and-a-half years as a senior, Augustinussen was stamped by a media pundit as being "not the fastest moped on the dockside" ("
ikke den hurtigste knallert på havnen") in August 2003, He suffered a knee injury in October 2006, but returned to the AaB side in August 2007, and helped the team win the
2007–08 Superliga championship. He was named team captain from the beginning of the 2008–09 season, and led AaB in the
2008-09 UEFA Champions League tournament. In total, he played 283 games and scored 36 goals for AaB, including 223 games and 29 goals in the Superliga until May 2009. In April 2009, he signed a three-year contract with
Austrian club
FC Red Bull Salzburg, effective from July 2009. After one-and-a-half year in Salzburg, Augustinussen was released from Salzburg of his own will. On 30 January 2011 AaB announced that they had signed Augustinussen on a three-year contract. Three years later in the
2013-14 Danish Superliga season, Augustinussen and AaB won "The Double". It was the first time ever, that the club won the league and captured the
Danish Cup as well. Augustinussen was captain in the historical season. ==Coaching career==