Having evangelized the districts of Goudrou, Lagamara, Limmou, Nonna, and Guera, Massaia entered the Kingdom of Kaffa on 4 October 1859, where conversions were abundant.
He provided the converted tribes with priests, so that when persecution obliged him to flee, Christianity did not disappear.
In 1868, Massaia was at Shewa, where he worked until 1879, and enjoyed the confidence of Menelik II of Ethiopia, who made him his confidential counsellor.
In the interval the missions of Kaffa and Guera were administered by his coadjutor Bishop Felicissimo Coccino, who died 26 February 1878.
In 1879 Negus John of Abyssinia compelled his vassal Menelik to order Bishop Massaia to return to Europe.