Depicts a tuna turned right. Above the tuna around the upper edge is written Latin name of tuna (THUNNUS THYNNUS). Around the lower edge, in the central part, is written the year of minting. Engraver's initials KK under the fish.

The Atlantic bluefin tuna (Thunnus thynnus) is a species of tuna in the family Scombridae. It is variously known as the northern bluefin tuna (mainly when including Pacific bluefin as a subspecies), giant bluefin tuna (for individuals exceeding 150 kilograms (330 lb)) and formerly as the tunny.

In the central part is shown stylized linden branch in inflorescence and on the leaves is written the value of the coin (20). Under the number is written inscription LIPA (linden) in Croatian. Around the top edge is written The Republic of Croatia. Around the lower edge, in the central part, is the coat of arms of the Republic of Croatia surrounded by the old Croatian braided ornaments.

The coat of arms of the Republic of Croatia consists of one main shield and five smaller shields which form a crown over the main shield. The main coat of arms is a checkerboard (chequy) that consists of 13 red and 12 silver (white) fields. It's also informally known in Croatian as šahovnica ("chessboard", from šah, "chess"). The five smaller shields represent five different historical regions within Croatia.