20 Centavos

São Tomé and Príncipe's first dedicated coinage series was issued under Portuguese colonial administration in 1929, replacing the practice of circulating mainland Portuguese coins on the islands. The territory had no mint of its own; these pieces were struck in Lisbon for colonial distribution across what was then a modestly productive cacao-exporting economy.

Nickel brass was the chosen alloy largely because of its durability in tropical climates, where humidity accelerates corrosion in lower-grade copper issues. Genuine uncirculated survivors are scarce — the islands' small population and active trade circulation ensured most examples saw considerable use.