Hancock describes himself as an “unconventional thinker who raises controversial questions about humanity’s past”. Prior to 1990 his works dealt mainly with problems of economic and social development. Since 1990 his works have focused mainly on speculative connections he makes between various archaeological, historical, and cross-cultural phenomena.
His books include Lords of Poverty, The Sign and the Seal, Fingerprints of the Gods, Keeper of Genesis (released in the US as Message of the Sphinx), The Mars Mystery, Heaven’s Mirror (with wife Santha Faiia), Underworld: The Mysterious Origins of Civilization, and Talisman: Sacred Cities, Secret Faith (with co-author Robert Bauval). In 1996 he appeared in The Mysterious Origins of Man. He also wrote and presented the documentaries Underworld: Flooded Kingdoms of the Ice Age (2002) and Quest for the Lost Civilisation (1998) shown on Channel 4.
In Hancock’s book Talisman: Sacred Cities, Secret Faith, co-authored with Robert Bauval, the two put forward what sociologist of religion David V. Barrett called “a version of the old Jewish-Masonic plot so beloved by ultra-right-wing conspiracy theorists.” They suggest a connection between the pillars of Solomon’s Temple and the Twin Towers, and between the Star of David and The Pentagon. A contemporary review of Talisman by David V. Barrett for The Independent pointed to a lack of originality as well as basic factual errors, concluding that it was “a mish-mash of badly-connected, half-argued theories”. In a 2008 piece for The Telegraphreferencing Talisman, Damian Thompson described Hancock and Bauval as fantasists.