Background: Cochlear implant is becoming the treatment of choice for bilateral sensorineural severe and profound hearing loss .The success of the implant and satisfaction of the patient are highly dependant on many factors, one of them is the appropriateness of the speech processor programming. The use of objective measure is needed to help speech processor programming. The electrically evoked compound action potential (ECAP), which can be assessed by neural telemetry is one of those objective measures. Another common objective measure used to assess device and electrode function is impedance. Telemetry is used to measure information such as electrical impedance and intracochlear neural response recordings. In this way the state of the cochlea and electrode can be monitored. Objectives: To monitor changes in recorded Impedance and ECAP intraoperatively versus the postimplant follow up visits ; to correlate recorded ECAP with the postoperative performance and to evaluate the incidence of abnormal intra-operative cochlear implant telemetry measurements and their changes at device activation. Subjects and Methods: The present study comprised 44 subject, 12 adults and 32 children of both genders. 20 subjects implanted with MED-EL device and 24 subjects implanted with CI24M between January 2011 and January2013.Inclusion criteria 1) Patients used their implant for at least 1 yr after device connection, and 2) they had participated in the necessary data collection at a minimum number of the time intervals assessed in this study. ECAP threshold, and electrode impedance measures were collected intra operatively, at initial stimulation, and at 9-12 months post initial stimulation.Results: In absence of electrical stimulation, there is an increase of impedance on all electrodes at initial stimulation visit. After activation, the impedance values decreased at the 9-12 month postimplant visit. Results indicate at least 1 open (OC) or short circuit (SC) in 9% (4/44) of devices intraoperative, remaining the same postoperatively. OCs were more prevalent than SCs for intraoperative devices (75% versus 25%). ECAP thresholds measured postoperatively were lower than those measured postoperatively. Basal electrodes had higher ECAP thresholds than apical electrodes. No correlation existed between ECAP thresholds and post operative performance at the 1-year evaluation.Conclusion: At the time of surgery, Neural Telemetry provides valuable information regarding the electrical output of the implant and theresponse of the auditory system to electrical stimulation and preliminarydevice programming data; however, it is not a valuable predictor of postoperative performance.