Soehnlein studied film in Ithaca College, then moved to New York City in the late 1980s, working in film production and magazine publishing, and was a member of ACT UP and Queer Nation. He worked as a journalist, writing mainly on films in Out, The Advocate, The Village Voice and other publications. Living in San Francisco, he made his living as a freelance writer and aspiring author. He studied at San Francisco State University graduating with an Master of Fine Arts and became the associate editor of the monthly film magazine, Release Print, as well as the manager of the Film Arts Foundation website. He wrote a number of essays as well as short stories that were published in Modern Words and The James White Review publications. He also worked as a freelance copywriter and editor.

His first novel published in 2000 entitled The World of Normal Boys was a big success and was translated into Italian. It also landed him a creative writing teaching job at the University of San Francisco and San Francisco State University and a collaboration with filmmakers Rob Epstein and Jeffrey Friedman for a movie adaptation of the novel, with Soehnlein as screenwriter. Soenlein already has screenwriting experience for writing for the 2005 film The Second Coming by director Jack Walsh

His second novel You Can Say You Knew Me When took about four years to write. He is writing now a third novel about the AIDS activist movement in New York and is planning on publishing a collection of his short stories as well.

He lives in San Francisco's SoMa district with his partner Kevin Clarke, a graphic designer.

• 2000: The World of Normal Boys
• 2005: You Can Say You Knew Me When

He has published a great number of short stories and has written essays in the anthologies:

• Girls Who Like Boys Who Like Boys
• Gay Men Write About Growing Up
• Bookmark Now: Writing in Unreaderly Times (his essay entitled "Putting Gay Fiction Back Together")

He is also the screenwriter of The Second Coming, a 2005 film by director Jack Walsh about the futuristic story of Carlos and Ben who fall in love in high school despite the racism and homophobia