El Hassan el-Abbassi gained his first international experience at the Zhuhai International Half Marathon 2011, which he won in 1:01:38 h. In 2013 he won the Marrakech half marathon in 1:01:09 h and then decided to start for Bahrain. In 2014, at the Asian Games in Incheon, South Korea , he won the gold medal over 10,000 meters in 28: 11.20 m ahead of the Japanese Suguru Ōsako . In 2015 he was 15th at the World Cross Country Championships in Guiyang and won the bronze medal in the team competition. At the Asian Championships in Wuhan , he also won the gold medal over 10,000 meters; this time he prevailed against the Indian Lakshmanan Govindan . This gave him a bye for the World Championships in Beijing , where he finished twelfth in the final . In October he also won gold at the Military World Games in Mungyeon . In 2016 he qualified over this distance for the Olympic Games in Rio de Janeiro , where he finished 26th in 28: 20.17 minutes . In 2017 and 2018 he won the Berkane half marathon and in 2017 the Marrakech half marathon. 2018 he participated in the IAAF World Half Marathon Championships in Valencia in part and was there with a time of 1:01:41 h 21. At the Asian Games in Jakarta , he won in 2:18:22 hours the silver medal in the marathon behind the Japanese Hiroto Inoue , who finished at the same time with him. He is the only marathon runner with a running time below 2:05:00 who is not from Kenya or Ethiopia (as of August 6, 2019).
In 2012 el-Abbassi became the Moroccan champion in the 10,000 meter run .
Personal best
5000 meters: 13: 19.36 min, July 9, 2016 in Barcelona
10,000 meters: 27: 25.02 min, May 29, 2015 in Eugene