His films covered a wide range of topics including communism, espionage, the historical authenticity of Noah's Ark, the Federal Reserve System, the Supreme Court of the United States, terrorism, subversion, foreign policy, electronic voting fraud, cancer, and the chemtrail conspiracy theory.

[14] Edward Flaherty, an academic economist writing for Political Research Associates, characterized Griffin's description of the secret meeting on Jekyll Island as "amateurish" and "highly suspect".

While he describes his work as the output of "a plain vanilla researcher," Griffin also agrees with the Los Angeles Daily News's characterization of him as "Crusader Rabbit".

[21][22] From 1962 to 1975, he completed nine books and seven film productions; Griffin's 1969 video lecture, More Deadly Than War: The Communist Revolution in America, was printed in English and Dutch.

[23][24] In May 2009, Griffin helped Robert L. Schulz and Edwin Vieira organize a meeting at Jekyll Island of thirty people which, according to the Southern Poverty Law Center, included tax protesters, militiamen, nativists, anti-Obama 'birthers,' libertarians, conspiracy-minded individuals with theories about FEMA death camps, and even an anti-Semite named Edgar Steele.

[25] Speakers at the meeting "warned of 'increasing national instability,' worried about a coming 'New World Order', denounced schemes to merge Canada, Mexico and the United States, and attacked the new president's 'socialized' policies and failure to end illegal immigration", and attendees made plans for a "continental congress" that occurred in November 2009 that was hosted by the We the People Foundation.

'"[25] Griffin founded the Freedom Force International, host of an annual convention called "Red Pill Expo", beginning with the first event in Bozeman, Montana in 2017.

[32][33][34] Emanuel Landau, then a Project Director for the APHA, wrote a book review for the American Journal of Public Health, which noted that Griffin "accepts the 'conspiracy' theory ... that policy-makers in the medical, pharmaceutical, research and fund-raising organizations deliberately or unconsciously strive not to prevent or cure cancer in order to perpetuate their functions".

Landau concludes that although World Without Cancer "is an emotional plea for the unrestricted use of the Laetrile as an anti-tumor agent, the scientific evidence to justify such a policy does not appear within it.

[4] Griffin's film said that the original Noah's Ark continued to exist in fossil form at the Durupınar site, about 17 miles (27 km) from Mount Ararat in Turkey, based on photographic, radar, and metal detector evidence.