We relate the components proposed by López et al. (2014) in their knowledge based development index with the main dimensions of a Smart City. We propose two ttechnological efficiency indices for the use and capability in ICT. We analyse the influence of two factors related with the use and capability in ICT on the different dimension of a Smart City. The results allow us to corroborate that these factors clearly influence economic development. The most important factor is the capability factor with a clear influence over human and image capital, and the use factor on environmental capital.