Pozzolo Formigaro borders the following municipalities: Bosco Marengo, Cassano Spinola, Novi Ligure, Tortona, and Villalvernia.
Cassano Spinola borders the following municipalities: Carezzano, Gavazzana, Novi Ligure, Pozzolo Formigaro, Sant'Agata Fossili, Sardigliano, Serravalle Scrivia, Stazzano, and Villalvernia.