Molecular or polymeric pi-electron donors based on the association of tetrathiafulvalene (TTF) with linear pi-conjugated systems are reviewed. Two main classes of materials are considered, namely electrogenerated polymers, either conjugated or not, and linearly extended TTF analogues built by insertion of different pi-conjugating spacer groups between the two 1,4-dithiafulvenyl moieties. Particular emphasis is placed on the relationships between structure and electronic properties and on the potential offered by these new classes of pi-electron donors.