structural:expansion
Themes and forms

In his introduction to Brodsky's Selected Poems (New York and Harmondsworth, 1973), W. H. Auden described Brodsky as a traditionalist lyric poet fascinated by "encounters with nature,... reflections upon the human condition, death, and the meaning of existence". He drew on wide-ranging themes, from Mexican and Caribbean literature to Roman poetry, mixing "the physical and the metaphysical, place and ideas about place, now and the past and the future". Critic Dinah Birch suggests that Brodsky's " first volume of poetry in English, Joseph Brodsky: Selected Poems (1973), shows that although his strength was a distinctive kind of dry, meditative soliloquy, he was immensely versatile and technically accomplished in a number of forms."

To Urania: Selected Poems 1965–1985 collected translations of older work with new work written during his American exile and reflect on themes of memory, home, and loss. His two essay collections consist of critical studies of such poets as Osip Mandelshtam, W.H. Auden, Thomas Hardy, Rainer Maria Rilke and Robert Frost, sketches of his own life, and those of contemporaries such as Akhmatova, Nadezhda Mandelshtam, and Stephen Spender.

A recurring theme in Brodsky's writing is the relationship between the poet and society. In particular, Brodsky emphasized the power of literature to affect its audience positively and to develop the language and culture in which it is situated. He suggested that the Western literary tradition was in part responsible for the world having overcome the catastrophes of the twentieth century, such as Nazism, Communism, and two World Wars. During his term as Poet Laureate, Brodsky promoted the idea of bringing the Anglo-American poetic heritage to a wider American audience by distributing free poetry anthologies to the public through a government-sponsored program. Librarian of Congress James Billington wrote:

Joseph had difficulty understanding why poetry did not draw the large audiences in the United States that it did in Russia. He was proud of becoming an American citizen in 1977 (the Soviets having made him stateless upon his expulsion in 1972) and valued the freedoms that life in the United States provided. But he regarded poetry as "language's highest degree of maturity", and wanted everyone to be susceptible to it. As Poet Laureate, he suggested that inexpensive anthologies of the best American poets be made available in hotels and airports, hospitals and supermarkets. He thought that people who are restless or fearful or lonely or weary might pick up poetry and discover unexpectedly that others had experienced these emotions before and had used them to celebrate life rather than escape from it. Joseph's idea was picked up, and thousands of such books have in fact been placed where people may come across them out of need or curiosity.

This passion for promoting the seriousness and importance of poetry comes through in Brodsky's opening remarks as the U.S. Poet Laureate in October 1991. He said, "By failing to read or listen to poets, society dooms itself to inferior modes of articulation, those of the politician, the salesman or the charlatan.... In other words, it forfeits its own evolutionary potential. For what distinguishes us from the rest of the animal kingdom is precisely the gift of speech.... Poetry is not a form of entertainment and in a certain sense not even a form of art, but it is our anthropological, genetic goal, our evolutionary, linguistic beacon." This sentiment is echoed throughout his work. In interview with Sven Birkerts in 1979, Brodsky reflected:

In the works of the better poets you get the sensation that they're not talking to people any more, or to some seraphical creature. What they're doing is simply talking back to the language itself, as beauty, sensuality, wisdom, irony, those aspects of language of which the poet is a clear mirror. Poetry is not an art or a branch of art, it's something more. If what distinguishes us from other species is speech, then poetry, which is the supreme linguistic operation, is our anthropological, indeed genetic, goal. Anyone who regards poetry as an entertainment, as "a read", commits an anthropological crime, in the first place, against himself.