El-Idrissi finished fourth in 4 × 400 m relay at the 2004 World Indoor Championships, together with teammates Alain Rohr, Martin Leiser and Andreas Oggenfuss. Earlier, during the series, the same Swiss team had realised 3.04,09, a new national record. He also participated at the 2004 Olympic Games, and finished eighth at the 2005 Summer Universiade.