He is best known for his five books: Voices of Brookline; American Jews and America's Game; his baseball memoir, My Eighty-Two Year Love Affair with Fenway Park: From Teddy Ballgame to Mookie Betts; his memoir, Larry Ruttman: A Life Lived Backwards: An Existential Triad of Friendship, Maturation, and Inquisitiveness; and Intimate Conversations: Face to Face With Matchless Musicians, scheduled for publication on October 1, 2024.

In 2019, Ruttman led an effort at the Brookline Town Meeting to rename the former Edward Devotion School in honor of Ethel Weiss, the owner of a nearby toy and card shop, who welcomed neighborhood children into her store for more than 76 years.

Ruttman's papers on his first two books, Voices of Brookline and American Jews and America's Game, have been collected by the Wyner Family Jewish Heritage Center (JHC), formerly of the American Jewish Historical Society, and now in collaboration with and at the New England Historic Genealogical Society in Boston, Massachusetts, and collated, digitized, formatted, indexed, and published worldwide online.

Ruttman's career as a published writer began at age 67, when he accompanied the members of a Plymouth, Massachusetts rowing club to the World Pilot Gig Championships on the Isles of Scilly in the United Kingdom.

[13] Ruttman self-published Voices of Brookline through Peter E. Randall Publisher LLC in 2005; Michael Dukakis, former governor of Massachusetts and 1988 presidential candidate, wrote the foreword.

In addition to Dukakis, television journalist Mike Wallace, and Boston Symphony Orchestra conductor Harry Ellis Dickson, the book's subjects include journalist Ellen Goodman; architecture critic and author Jane Holtz Kay; Nobel Prize-winning physicist Wolfgang Ketterle; New England Patriots owner Robert Kraft; composer Osvaldo Golijov; pianist and composer Ran Blake; many ordinary citizens involved in town government, education, preservation, and other pursuits; and two notable sports venues, the Longwood Cricket Club (site of the first Davis Cup) and The Country Club (which hosted the 1999 Ryder Cup and the 2022 U.S. Open Championship).

Boston University professor and historian Howard Zinn wrote of Voices of Brookline, "[This] book is a model of how an oral history of a town ought to be written.

American Jews and America's Game was selected for the National Library Service for the Blind and Physically Handicapped Talking Book Program.

[27] Longtime sportswriter and Red Sox team historian Gordon Edes described it as "an unmatched, and highly personal, view of what it meant to have a front-row seat on Fenway Park history.

Written largely during the pandemic,[31][32] the book covers Ruttman's early life, legal practice, friendships, and second career as an interviewer, author, and storyteller.

[2] Matthew Sutherland, executive editor of Foreword Reviews, extensively interviewed Ruttman about Intimate Conversations, which drew from the author comprehensive remarks on the book, its underlying purpose, his passionate feelings about music and life, and the relationship of one to the other.

[35] In the program, “historian Larry Ruttman of Brookline, Eddie Romero Jr of the Boston Red Sox general management, and Jordan Rich of WBZ Radio share their personal reminiscences about living in America with baseball as a backdrop – a retrospective spanning almost ninety years.

In each episode, Boston radio host Jordan Rich interviews Ruttman about the people, places and experiences that have shaped him and contributed to his life adventure.