Bishop Arquimínio Rodrigues da Costa was from the Azores Islands in Portugal. He first came to Macao in 1938 and studied in the St. Joseph's Seminary. After his ordination in 1949 he had been the seminary's Prefect of Discipline, professor and rector. In 1959 he was conferred the Licentiate's Degree in Canon Law in Rome. In 1963 and 1965 he took up the post of Diocesan Administrator. In 1973 he was appointed the Vicar Capitular. In 1976 Pope VI nominated him the Bishop of Macao and the consecration ceremony took place in the Cathedral on 25th March the same year . He retired in 1988 and returned to the Azores Islands in Portugal.