A décima is a ten-line stanza of poetry. The most popular form is called décima espinela after Vicente Espinel (1550–1624), a Spanish writer, poet, and musician from the Siglo de Oro who used it extensively throughout his compositions.

The décima deals with a wide range of subject matters, including themes that are philosophical, religious, lyrical, and political. Humorous décimas would typically satirize an individual's weakness or foolish act. A decimero would frequently challenge the target of the satire or his/her defender to respond in kind with a décima, thereby setting up a duel that tests the originality and wit of contending composers.

Latin America and Spain

The décima in all Latin America and in Spain is a style of poetry that is octosyllabic and has 10 lines to the stanza. The espinela rhyming scheme (ABBAACCDDC) is the de facto scheme in use. It is spoken, sung and written throughout Latin America with variations in different countries. It is often improvised.

Each country has its own melody and tone ("tonada") and a different instrument, but the style and structure is exactly the same. A person who writes or improvises décima is known as a decimista or decimero.

Décima Afro-Pacífica

The décima afro-pacífica is an extension of the décima espinela into four décima stanzas with an introductory four-line stanza (or copla) that often summarizes the entire work using the 10th line of each décima stanza, making a total of forty four octosyllabic lines (one quatrain plus four décima espinelas).

The term "octosyllabic" may be misleading to English speakers as in Spanish the term refers to "metric syllables", meaning that the number of syllables is counted by the amount of spoken syllables the line carries. For example the line "Allá arriba en esa loma" carries ten grammatical syllables, but when spoken naturally it sounds like "A lláa rri baen e sa lo ma" which amounts to 8 spoken syllables. The variations based on the word's accents (agudas, graves, and esdrújulas) in the last word of the verse also allows for different numbers of metric syllables:

• If ending in an "aguda" word like "corazón" the line should have 7 metric syllables.
• If ending in a "grave" word like "loma" the line should have 8 metric syllables.
• If ending in an esdrújula word like "brújula" then the line should have 9 metric syllables.