Еhe central part of the coin's core carries the symbol of the Congress, an elliptic circle within which eight elongated rhombs are placed in two vertical columns, pointing at one another with their tips. Of the five rhombs in the left column, the third and the fifth are filled with vertical lines. The right column contains three rhombs, all filled with vertical lines, symbolizing the red and white fields of the Croatian historical coat of arms. All eight rhombs are connected, forming the capital letter "E" (i.e. Esperanto). An identical rhomb is placed centrally at the lower part of the ring, with the inscription "First Congress of Croatian Esperanto" in Esperanto beginning on the left side of the rhomb and stretching along the ring to its right side. The second, inner, strip of the ring's surface features the inscription "First Congress of Croatian Esperanto" in Croatian, separated by the minting year, placed centrally in the lower part of the strip, above the elongated rhomb.

The central part of the coin's core carries the designation of the nominal value 25. Within the numeral outlines, the figure of a pine marten running towards the right is shown; the marten's body is integrated with the numeral denoting the nominal value. In the bottom, central part of the coin's ring the coat of arms of the Republic of Croatia is impressed. A blooming laurel branch is placed in a semicircle on the left to the coat of arms, while a common oak branch with fruits is on the right. The top part of the ring carries the semicircular inscription The Republic of Croatia.

The word "kuna" means "marten" in Croatian since it is based on the use of marten pelts as units of value in medieval trading.

The martens are slender, agile animals, adapted to living in taigas, and are found in coniferous and northern deciduous forests across the Northern Hemisphere. They have bushy tails, and large paws with partially retractible claws. The fur varies from yellowish to dark brown, depending on the species, and, in many cases, is valued by fur trappers.

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.