Abstract: A gas burner apparatus with pre-mixing includes a mixing device for mixing an air/gas mixture which is intended to be conveyed to the intake section of a fan unit whose delivery is conveyed to a combustion head of the burner. The mixing device including a plurality of ducts, each of which has a region in the form of a Venturi duct with contiguous portions which are convergent/divergent, with respect to the direction of flow, and with a restricted duct cross-section defined between the convergent portion and the divergent portion, there being conveyed in each convergent portion an air flow which is intended to be mixed with a gas flow which is introduced into the duct at the restricted cross-section, the air/gas mixture being conveyed through the divergent portion of the duct to the intake section of the fan unit.