Eloisa Coiro gained her first international experience at the 2016 European Youth Championships in Tbilisi , where she made it to the semi-finals in the 400-meter run and was eliminated there with 56.98 seconds. In addition, it was used in the sprint relay (1000 meters) in the run-up and thus contributed to winning the bronze medal. The following year she finished fifth over 800 meters at the U20 European Championships in Grosseto in 2: 07.79 minutes. In 2018 she was eliminated from the U20 World Championships in Tampere with 2: 06.85 min in the semifinals and reached sixth place in the Italian 4 x 400 meter relay in 3: 34.00 min. In 2019 she was fourth in the U20 European Championships in Borås, Sweden in 2: 04.12 min.
In 2019 Coiro became the Italian champion in the 800-meter run.