Perl played his first international competition in 2001 at the Continental Cup in his home town of Campra . There he could only place himself in the back of the field. In the following years he continuously increased his performance and was nominated for the Junior World Championships in Sollefteå in 2003 . Over 30 kilometers freestyle (mass start) he took a good twelfth place and over 10 kilometers classic 23rd place. A year later he was able to improve these results significantly at the Junior World Championships in Stryn, Norway and won the silver medal over 30 kilometers classic (mass start) and finished ninth over 10 kilometers freestyle. He finished eighth with the Swiss team. He also increased his performance in the Continental Cup and was able to fight for second place in the overall standings with several top ten results. In March 2005 he started in the cross-country skiing world cup for the first time . In Falun he was 49th out of 71 starters over 30 kilometers freestyle. A year later, he was able to improve this result significantly with place 35. At the newly introduced U23 World Cup, he achieved 12th place in 2006 in Kranj over 15 kilometers.
Perl's breakthrough in the senior sector came in the 2006/07 season when he unexpectedly came in tenth in his third World Cup appearance in Davos . This result brought him the nomination for the Nordic World Ski Championships 2007 in Sapporo . There he was 29th in the 15 kilometer freestyle and 30th in the pursuit competition, as well as tenth with the Swiss cross-country relay. At the subsequent U23 World Championship in Tarvisio , he finished fifth when his compatriot Dario Cologna won over 15 kilometers of freestyle. In the pursuit competition he sprinted the silver medal behind Cologna. Perl has been a permanent member of the Swiss World Cup team since the 2007/08 season . In his very first season he was able to regularly collect World Cup points in distance competitions. Like the entire young Swiss team, Perl continued its upward trend in the 2008/09 season . At the 2009 World Championships in Liberec , Czech Republic , he was 26th in the mass start race over 50 kilometers, while he finished seventh in the relay. At the 2010 Winter Olympics in Vancouver , Canada , he was 17th in the classic technique over 15 kilometers, 20th in the pursuit race over 30 kilometers and tenth in the Swiss cross-country relay.
At the Tour de Ski 2010/2011 , Curdin Perl came fourth behind the Swiss Dario Cologna , the Norwegian Petter Northug and the Czech Lukáš Bauer , making him one of the best in the world. Nevertheless, at the 2011 World Championships in Oslo, Norway, he was only used in the mass start race over 50 kilometers, in which he was 44th, and in the relay, with which he came in ninth. After a difficult 2011/12 season, Perl finished in 11th place over 15 kilometers in free technique at the season opener in Gällivare, Sweden, at the end of November 2012 . At the 2013 World Championships in Fiemme Valley , he took eleventh place over 15 kilometers in free technique, 14th place in skiathlon and 32nd place in mass start over 50 kilometers, while he finished sixth in the relay. At the 2014 Winter Olympics in Sochi , Russia , he finished 12th in the mass start race over 50 kilometers, 22nd over 15 kilometers in classic technique and 26th in the skiathlon, while he finished seventh in the Swiss cross-country relay.
At the 2017 World Championships in Lahti , Finland , he was 54th in the mass start race over 50 kilometers and, as the final runner in the Swiss relay team, missed his first World Championship medal just 0.2 seconds behind the Swedish team in fourth. For the Swiss it would have been the first relay medal since the 1972 Winter Olympics . He ran his last World Cup race so far on New Year's Eve 2017 as part of the Tour de Ski 2017/18 in Lenzerheide , when he was 65th in the race over 15 kilometers. Since then, he has competed in the Worldloppet Cup occasionally .