Electric Vehicles (EVs) have gained increased attention courtesy their potential to mitigate environmental issues associated with transportation. To integrate EVs in transportation and power networks, it is essential to properly perform the siting and sizing of charging stations. In particular, this task is more challenging for users that have more rigid schedules such as taxi drivers. This paper proposes a coordinated siting and sizing methodology for electric taxi (ET) charging stations considering both transportation and power system constraints. The case of Quito, Ecuador has been analyzed. The results indicate the optimal placement of the ET charging stations and the number of charging spots to be installed.