He played for a number of Danish clubs, most notably Boldklubben 1893 (B 93) in the Danish Superliga, as well as a number of foreign clubs (Sweden: Kiruna FF, England: Torquay United, Finland: Finnpa, China: Guangzhou Apollo, Norway: SK Gjøvik-Lyn).
He returned to Denmark in August 1997, following reports of cultural shock and poor living from Haddaoui and Danish teammate Kim Rasmussen.
In the same season, he won the topscorer prize in the Danish indoor championship for superleague clubs called BT cup.
Haddaoui joined Copenhagen rivals HIK in the 1st Division in 1999 and played for 2+1⁄2 seasons, making an impressive 48 goals.
He was still playing part-time for HIK in the Danish 2nd Division in the 2001–02 season, while working as a web consultant for webmagazine Ingeniøren.