She wrote a memoir in 1961 called Underfoot in Show Business[3] that chronicled her struggles as an ambitious young playwright trying to make it in the world of New York theatre in the 1940s and 1950s.

She became intimately involved in the lives of the shop's staff, sending them food parcels during Britain's postwar shortages and sharing with them details of her life in Manhattan.

Due to financial difficulties and an aversion to travel, she put off visiting her English friends until too late; Doel died in December 1968 from peritonitis from a burst appendix, and the bookshop eventually closed.

Hanff did finally visit Charing Cross Road and the empty but still-standing shop in the summer of 1971, a trip recorded in her 1973 book The Duchess of Bloomsbury Street.

[6] In Duchess, Hanff describes her visits with friends and fans to various locations and places of literary and historical interest in London and Southern England.

[citation needed] A memorial plaque stands at the McDonald's now in its location, reading "84 / CHARING CROSS ROAD / THE BOOKSELLERS / MARKS & CO. / WERE ON THIS SITE WHICH / BECAME WORLD RENOWNED / THROUGH THE BOOK BY / HELEN HANFF".

[9] Underfoot in Show Business was adapted as a stage play by Charles Leipart and premiered in 2008 at the Devonshire Theatre in Eastbourne, UK, directed by David Giles.

In the 1987 84 Charing Cross Road movie, a photo of a US serviceman is shown in her apartment during World War II, a portrait at which she smiles fondly, suggesting to the viewer that Hanff remained unmarried owing to this naval officer's death.

However, writer Al Senter claimed that she mentioned a long affair with an unnamed 'prominent American' during a conversation with one of the co-founders of Marks and Co,[10] and one obituary of her asserted that 'there were romances'.