Founded by conservative theologian John Gresham Machen in 1935, it acted as the de facto publication of the Orthodox Presbyterian Church, whose members made up most of its readership, despite being officially unaffiliated with any one denomination.

In 1979, it merged with The Presbyterian Journal, which had a significantly larger circulation and similar conservative theological stances.

James T. Dennison Jr., compiler of a cumulative index to the magazine, wrote that The Presbyterian Guardian was "conceived in controversy.

In response to perceived modernism in the magazine, Machen began publishing The Guardian with a small group of conservative ministers and laymen, hiring Rev.

In April 1978, the Board of Trustees asked J. Cameron Fraser, a native Scot who was then a graduate student at Westminster Seminary to take the position of Managing Editor for 14 months while they contemplated the newspaper's future.