The pantoum is a form of poetry similar to a villanelle in that there are repeating lines throughout the poem. It is composed of a series of quatrains; the second and fourth lines of each stanza are repeated as the first and third lines of the next. This pattern continues for any number of stanzas, except for the final stanza, which differs in the repeating pattern. The first and third lines of the last stanza are the second and fourth of the penultimate; the first line of the poem is the last line of the final stanza, and the third line of the first stanza is the second of the final. Ideally, the meaning of lines shifts when they are repeated although the words remain exactly the same: this can be done by shifting punctuation, punning, or simply recontextualizing.
A four-stanza pantoum is common, and in the final stanza, you could simply repeat lines one and three from the first stanza, or write new lines. The pantoum "recipe" is as follows:
Stanza 1 A B C D (or A C B D)
Stanza 2 B E D F (or C E D F)
Stanza 3 E G F H
Stanza 4 G I (or A or C) H J (or A or C) 
The pantoum is derived from the pantun berkait, a series of interwoven quatrains. An English translation of such a pantun berkait appeared in William Marsden's A Dictionary and Grammar of the Malayan Language in 1812. Victor Hugo published an unrhymed French version by Ernest Fouinet of this poem in the notes to Les Orientales (1829) and subsequent French poets began to make their own attempts at composing original "pantoums". Leconte de Lisle published five pantoums in his Poèmes tragiques (1884). Baudelaire's famous poem "Harmonie du soir" is usually cited as an example of the form, but it is irregular. The stanzas rhyme abba rather than the expected abab, and the last line, which is supposed to be the same as the first, is original.
American poets such as John Ashbery, Marilyn Hacker, Donald Justice ("Pantoum of the Great Depression"), Carolyn Kizer, and David Trinidad have done work in this form, as has Irish poet Caitriona O'Reilly. Stuart Dischell published a well-received pantoum, "She Put on Her Lipstick in the Dark," in the December, 2007 issue of The Atlantic. Neil Peart used the form for the lyrics of "The Larger Bowl (A Pantoum)" on Rush's 2007 album, Snakes & Arrows (with one difference from the format listed above).
There is also the imperfect pantoum, in which the final stanza differs from the form stated above, and the second and fourth lines may be different from any preceding lines.
Examples of pantoums
- "Pantoum of the Great Depression" by Donald Justice
- "Parent's Pantoum" by Carolyn Kizer (includes audio clip of poet reading the poem)
- "Harmonie du soir" by Charles Baudelaire (imperfect pantoum, in French; also includes four English translations)
- "I Am Going to Like It Here" by Oscar Hammerstein (and Richard Rodgers) (imperfect pantoum from the musical Flower Drum Song)
- 'On Beauty' by Nick Laird—a 'broken' pantoum (scroll down).
- 'Command' by Rachel Barenblat.