Frequently, the interiors of the Ethiopian basilicas built in the Christian ‘millennium' ranging from 5th-6th cent. to the end of the 15th cent. are adorned and embellished by serial motifs. Is it right to simply call ‘decorations’ these geometric patterns? If so intended they would just be an accessory. Actually, the presence of friezes, stuccos, paintings, etc. affixed to the structure or the elements of furniture is not only a manifestation of quality and mastery, but also an attempt to make more beautiful and glorious the buildings. The different typologies of internal decorations of the Ethiopian basilicas of Tigray and Lasta are here listed and studied according to their patterns and realizations.