Transparent conducting coatings of doped SnO
2
and Zn
2
SnO
4
have been deposited by the sol-gel technique on borosilicate and alumosilicate glass substrates, respectively. As films of SnO
2
:Sb (ATO) show some intrinsic drawbacks, which are discussed in this report, alternative dopants for SnO
2
such as Ta, Nb and W, were examined concerning the electrical and optical properties of the deposited coatings. In this way, coatings with resistivities on the order of 3 x 10
-2
Ωcm characterized by much higher charge carrier mobilities than for SnO
2
:Sb and a transmission of 85% were realized. In the search for ternary compounds (A
x
B
y
O
z
), coatings in the system ZnO-SnO
2
were examined, focusing on the fabrication of meta zinc stannate (Zn
2
SnO
4
). Coatings made from tin alkoxides yielded monophasic materials with high crystallinity and good morphological properties. By post-annealing, a resistivity of 0.4 Ωcm, with charge carrier mobilities of up to 7 cm
2
/Vs were obtained. Therefore, the development of the coating solution is as crucial as the elaboration of the heat treatment procedure of as-deposited films in order to obtain pure Zn
2
SnO
4
phase coatings without any impurity phases.