From what I've seen ( a Belgian map on organised crime) 6 or 7 italian (cosa nostra, Camorra, Ndrangheta) families are active in Belgium (Liege, Charleroi, Brussels) - 3 families are active in the northern part of the counry in a small city called Genk (which has a large italian population) - they are very low key there
Other than that there is also italian/belgian organised crime ran by the family Aquino but most of them got busted and they ar in jail now - can't say if they still run their business from jail
In the 90's La stidda was active in Liege - Stidda means star - Those sicilians had a pretty good sense of humor because they called their bar "l'etoile du sud" which means the star from the south