Barcelona has held a medicinal herb fair since the Middle Ages. In the 16th century it was decided to hold it on 11 May, the feast day of Sant Ponç. Today herbalists and crafts people line their stalls along Carrer de l'Hospital, in the Raval neighbourhood, where they have been since 1817, after passing through Plaça de Sant Miquel, Carrer de Sant Cugat del Rec and the area round Hospital de la Santa Creu.

The crowds of visitors who go there every year can find honey, fruit preserves, jam and marmalade, mató cheese, craft cheese, medicinal herbs and other products associated with eating and health. The fair is held in May because that is the time when most medicinal herbs blossom and are at their best.

The feast day of the patron saint of herbalists and beekeepers is also celebrated with other activities the Unió de Sant Ponç organises around this fair. On the night of 10 May, the saint's image is decorated with herbs and flowers to preside over the mass offered to him the following day, when it is taken in procession to bless the medicinal herbs that have been brought.