Brooks published her first poem in a children's magazine at the age of thirteen. By the time she was sixteen, she had compiled a portfolio of around 75 published poems. At seventeen, she started submitting her work to "Lights and Shadows," the poetry column of the Chicago Defender, an African-American newspaper. Her poems, many published while she attended Wilson Junior College, ranged in style from traditional ballads and sonnets to poems using blues rhythms in free verse.
Her characters were often drawn from the inner city life that Brooks knew well. She said, "I lived in a small second-floor apartment at the corner, and I could look first on one side and then the other. There was my material."
By 1941, Brooks was taking part in poetry workshops. A particularly influential one was organized by Inez Cunningham Stark, an affluent white woman with a strong literary background. Stark offered writing workshops to African-Americans on Chicago's South Side, which Brooks attended. It was here she gained momentum in finding her voice and a deeper knowledge of the techniques of her predecessors. Renowned poet Langston Hughes stopped by the workshop and heard Brooks read "The Ballad of Pearl May Lee." Brooks continued to work diligently at her writing and growing the community of artists and writers around her as her poetry began to be taken more seriously.
Brooks' published her first book of poetry, A Street in Bronzeville (1945), with Harper and Row, after strong show of support to the publisher from author Richard Wright. He said to the editors who solicited his opinion on Brooks' work,
"There is no self-pity here, not a striving for effects. She takes hold of reality as it is and renders it faithfully...She easily catches the pathos of petty destinies; the whimper of the wounded; the tiny accidents that plague the lives of the desperately poor, and the problem of color prejudice among Negroes."
The book earned instant critical acclaim for its authentic and textured portraits of life in Bronzeville. Brooks later said it was a glowing review by Paul Engle in the Chicago Tribune that "initiated My Reputation." Engle stated that Brooks' poems were no more "Negro poetry" than Robert Frost's work was "white poetry." Brooks received her first Guggenheim Fellowship in 1946 and was included as one of the “Ten Young Women of the Year” in Mademoiselle magazine.
Brooks' second book of poetry, Annie Allen (1950), focused on the life and experiences of a young Black girl as she grew into womanhood in the Bronzeville neighborhood of Chicago. It was awarded the Pulitzer Prize for poetry; she also was awarded Poetry magazine’s Eunice Tietjens Prize.
Brooks said her first teaching experience was at the University of Chicago when she was invited by author Frank London Brown to teach a course in American literature. It was the beginning of her lifelong commitment to sharing poetry and teaching writing.
Brooks taught extensively around the country and held posts at Columbia College Chicago, Northeastern Illinois University, Chicago State University, Elmhurst College, Columbia University, City College of New York, and the University of Wisconsin–Madison. In 1967 she attended a writers’ conference at Fisk University where, she said, she rediscovered her blackness. This rediscovery is reflected in her work In The Mecca (1968), a long poem about a mother searching for her lost child in a Chicago apartment building. In The Mecca was nominated for the National Book Award for poetry.
On May 1, 1996, Brooks returned to her birthplace of Topeka, Kansas. She gave the keynote speech for the Third Annual Kaw Valley Girl Scout Council's "Women of Distinction Banquet and String of Pearls Auction."
The Rare Book & Manuscript Library (University of Illinois at Urbana-Champaign) acquired Brooks' archives from her daughter Nora. In addition, the Bancroft Library at UC Berkeley has a collection of her personal papers, especially from 1950 to 1989.