Electrophysiology during cochlear implant surgery remains an issue of debate among the various centres. In the present study, the latencies and quality of the eABR waveforms from 74 adult implanted patients were analysed. In addition, four children with severe cochlear abnormalities were also reviewed. It was interesting to note that wave V in the mid- and low-frequency regions was the most robust and that significant latency shifts occurred in wave V from the low- to high-frequency regions. Although no correlations were found between waveform score, wave V–III interval, wave V latency, and MS-word scores, a negative eABR always predicted a negative outcome. The latter is associated with feelings of stimulation without actual hearing, very high levels in the tuning map postoperatively, and other negative parameters. Although the literature is more or less inconclusive, the results of this study support intraoperative electrophysiology taking into account the related limitations.