Adhesion between polyamide 6 (PA6) and thermoplastic vulcanizates in which tile continuous phase is polypropylene (PP) have been investigated through double beam cantilever tests. Both a precise control, on molecular scales, of the surface density of bloc copolymer molecules acting as adhesion promoters and systematic observation (for scales ranging from nano- to micrometric) of the plastic deformation zones developing at the crack tip are used to identify the adhesion mechanisms. As long as the plastic deformation zones remain localized Dugdale type zones, the adhesive strength is driven by the surface density of the copolymer molecules at the interface and quantitatively follows the Brown model, whatever the detailed architecture of the crack tip deformation zone.