In 1948, brothers Russell H. Varian, Sigurd F. Varian, and two other scientists with close ties to Stanford University (William Webster Hansen, Edward Ginzton) founded Varian Associates in San Carlos, California. Varian Associates in San Carlos, California. Brothers Russell and Sigurd Varian were the inventors of the tachyon tube, which later became a major component of modern medical linear gas pedals.
In 1953, Varian Associates opened its headquarters in Palo Alto, California.
In 1959, Varian Associates was listed on the New York Stock Exchange.
In 1994, Varian Associates entered the brachytherapy market with a line of products for use in brachytherapy.
In 1997, the introduction of Varian Union's SmartBeam technology marked the beginning of the era of intensity modulation in radiotherapy.
In 1999, Varian Associates changed its name to Varian Medical Systems after separating from its semiconductor manufacturing equipment and scientific instrumentation businesses.