Many of his works were adapted into screenplays starting during the silent film era, particularly his first novel, The Three Godfathers, which was published in 1913 and proved to be a huge success.

[2] Young Kyne worked on his father's ranch in San Francisco, then attended a business college where he decided to become a writer.

[2] When still younger than 18 years old, Kyne lied about his age and enlisted with Company L, 14th U.S. Infantry nicknamed "the Golden Dragons", which served in the Philippines from 1898 to 1899.

The Spanish–American War and the struggle for Philippine independence led by General Emilio Aguinaldo provided background for many of Kyne's later stories.

He described how he took a .32-calibre revolver and "felt for the fifth rib ... cocked the pistol, thrust the barrel to the spot ... and pulled the trigger.