[2] It is known, from oral investigations, that one of the first civil parishes created on the island of Pico was dedicated to the apostle Mathew, and which extended along the southern coast in an area considerably larger than today's limits.

[3] It was, then, part of the locality of Arruda, its centre 12 kilometres (7.5 mi) from Lajes, and whose name was derived from a medicinal plant discovered in the region.

The pie-shaped parish extends from the southern coast to the interior, sloping from rugged cliffs to the mountainous summit of Ponta do Pico.

In addition to the parish center of São Mateus (location of the primary school, commercial businesses and civil government), located near the São Caetano border, the coastal village of Areeiro in the southwest corner and the interior hamlet of Ginjeira, are the predominant rural agglomerations.

Other localities are Badgaço, Canada Nova, Grotas, Grotas de Cima, Mata, Paço, Ponta da Calheta, Porto Novo, Porto de São Mateus, Pontinha, Relvas and Rua dos Caldeirões.