Rutkowski started in the FIS Cup in 2004 . At the 2006 Junior World Championships in Kranj , Slovenia , he narrowly missed a podium finish as fourth in the individual competition. He then competed in the Ski Jumping Continental Cup (COC) for the rest of the 2005/06 season and was able to place in the top 20 several times. At the beginning of the 2006 COC summer competitions he was able to jump into ninth place in Velenje , but continued to fight for a place in the second round as the summer progressed. In the winter of 2006/07 he was only able to call up moderate performance in the COC and also missed the second round in the 2007 Junior World Championship in Tarvisio as 31st. At the 2007 COC summer competitions, he also always placed outside the points. After starting the 2007/08 winter season a little better, he was able to improve in January 2008 and once again achieve a result among the top ten with an eighth place in Kranj. At the end of January he was able to qualify for a World Cup competition for the first time in Zakopane and reached 38th place. In the further course of the winter he was able to place himself in the points several times in the COC and, especially towards the end of winter, also celebrate some results among the top ten. At the Junior World Championships in Zakopane in 2008 he narrowly missed a medal in the individual competition in fourth place, but was able to win the bronze medal with the team. He also took part in four competitions of the FIS Cup in the winter of 2007/08, of which he was able to win two. After he always finished midfield at the COC summer competitions in July 2008, he started the summer Grand Prix in August . Here, with the exception of the season final jumping in Liberec, he was always able to reach the second round. When jumping on August 31, 2008 in Zakopane, he celebrated his first podium with a third place. In the 2008/09 winter season, Rutkowski initially always took part in the World Cup, but always missed the qualification for the first round. Only when jumping in Engelberg could he take part in the actual competition after having passed the qualification. With a 27th place, he was able to achieve the first World Cup points of his career here. After he had only finished 67th in the qualification for the Four Hills Tournament in Oberstdorf , he was not considered for the Polish team for the qualification for the New Year's competition in Garmisch-Partenkirchen . On March 21, 2009 he jumped to second place with the Polish team in the team ski flying in Planica and thus achieved his only podium finish in the World Cup. At the Nordic World Ski Championships in Liberec in 2009 he took 4th place in the team competition with the Polish team.
His best World Cup results to date were achieved in January 2010 with 13th places in the ski flying in Tauplitz and the two jumping competitions in Sapporo .
Łukasz Rutkowski is the younger brother of Mateusz Rutkowski , the 2004 junior world ski jumping champion.