Corrosion susceptibility and the type of corrosion in AlMgSi alloys depend strongly on microstructure. However, it is still unclear what microstructural features trigger corrosion initiation. The direct correlation of second-phase particles with the corrosion propagation path has also never been thoroughly explored. In this work, the role of second-phase particles in corrosion initiation and propagation were studied in alloy AA6016 by using a microelectrochemically controlled microtomography technique. Three topics are discussed in detail, the role of Fe-containing intermetallics, the effect of MgSi particles, and an evidenced type of directed corrosion (exfoliation-like attack): (i) Intergranular corrosion initiates preferentially in Fe-containing intermetallics located at grain boundaries. However, its propagation path is not promoted by these intermetallics. (ii) MgSi particles do not act as transition sites to in-depth corrosion propagation, even if they dissolve. (iii) A type of corrosion called exfoliation-like attack is observed. It is characterized by straight attack into the bulk material. The propagation is found to be independent of grain boundaries and second-phase particles.