Investigation of electron cyclotron (EC) wave propagation, power absorption and current drive has been performed for a set of JET scenarios, aiming to assess the optimal wave frequency, launching position and injection angles to achieve the various physics goals of an EC system in JET. EC power absorption and current drive have been computed for three values of the EC frequency, namely 113, 150 and 170 GHz. In addition, the 136 GHz frequency has been considered as an option for a two-frequency gyrotron at 170 GHz. On the basis of extensive beam-tracing calculations performed in a wide range of magnetic fields (2.5–3.4 T), the frequency of 170 GHz has been chosen, since it covers the wider magnetic field range of operation in JET and corresponds to that foreseen in ITER. The performance at 170 GHz is presented in detail.