Electrostatic edge fluctuations were investigated by means of Langmuir probes on the ASDEX tokamak in lower hybrid current drive regimes, simultaneously with the global particle and energy balances. It was found that the edge fluctuations are reduced and the global particle/energy confinement improves when the LH power is below the initial ohmic power. The maximum reduction of the fluctuations and the best confinement occur when the total power input (OH + LH) is minimum. With a LH power higher than the initial OH value, the fluctuation level increases noticeably, while no improvement of the global confinement is observed. The increase of the edge fluctuations seems to be poloidally localized and caused by local power deposition in front of the grill antenna. Therefore, the relative positions of the probe and antenna structure have to be taken account for correct interpretation of the fluctuation data. (orig.).