There she found out about the other two homophile organizations, the Mattachine Society and Daughters of Bilitis (DOB) in San Francisco.

Gittings marks her official association with the movement two years later, in 1958, when she was asked to help start the New York Chapter of DOB, even though she lived in Philadelphia. She spent two weekends a month "up the road," serving as the chapter's first president. In 1961, at a DOB social gathering, Gittings met her current companion and lover, Kay Tobin Lahusen. Their courtship took place in Boston and New York, but eventually Gittings persuaded Lahusen to join her in Philadelphia.

In 1963, Gittings became editor of the Ladder, the DOB magazine, a "temporary job" which lasted until mid-1966. "Once I started I found I really liked it. I liked the power of the editor to shape the content of the magazine and to shape the readers' attitudes. I found that this was a way I could make a real difference," Gittings reflects. Working on the Ladder was a family project: "Kay was really co-editor although her name didn't appear on the masthead." Together the couple implemented several changes in the magazine, slowly bringing the magazine itself out of the closet. They strove to "crack the cocoon of invisibility" by adding the subtitle "A Lesbian Review" and featuring photographs of real lesbians on the cover. They also began distributing the Ladder through bookstores. One Greenwich Village store displayed the magazine right by the cash register and sold over 100 copies a month. "It was a victory to have it publicly sold instead of only circulated by mail," Gittings comments, "It was important to do this because in the early '60s people had strange ideas of what lesbians were like. This way they could see lesbians as happy, healthy, wholesome human beings."

While still with the Ladder, Gittings became active with the East Coast Homophile Organizations (ECHO) and later the Homophile Action League, plunging into social activism and relentlessly staging pickets and protests. In 1971, she became involved in the effort to get the American Psychiatric Association (APA) to drop its listing of homosexuality as a mental illness. The campaign was successful and in 1973, the APA Board of Trustees voted to remove homosexuality from the list of mental disorders.

In 1970, Gittings began her 16-year association with the American Library Association (ALA). Books and libraries had played a significant role in Gittings' life, and so although she was not a professionally trained librarian, when she discovered ALA's new Task Force on Gay Liberation she joined immediately. Before long, she became the task force coordinator. Under her guidance, the task force promoted its annual Gay Book Award (the first gay literary award), issued increasingly larger bibliographies and reading lists, presented thought-provoking programs, and agitated for policy changes. The article, "Gays in Library Land," relates Gittings' experiences with the task force.

Since leaving the task force in 1986, Gittings has spent her time lecturing and conducting workshops. Asked about her plans for the future, Gittings responded: "Kay and I are encouraging the creation of gay retirement homes. We've built our social lives in the gay community, and we know lots of us wouldn't feel right in a hetero retirement setting. We want to be with our own gay-and-gray friends."