As with many surgical procedures, different surgeons take different techniques and approaches in cochlear implant surgery. However, there are some basic principles that determine cochlear implant surgery. (i) insert the electrode into the tympanic step as noninvasively as possible; (ii) place the device on the outside of the head and avoid future trauma; and (iii) ensure that the device and electrode array are firmly positioned to prevent displacement. The goal is to preserve the surrounding tissues and complete the implantation procedure under conditions that do not damage the device and electrode array, do not cause infection, and have an acceptable appearance. In general, improvements in the physical and structural characteristics of the implanted device determine improvements in surgical technique. Surgical technique is essentially the same in children and adults, with no increased risks or contraindications in young children (12 months and older), although some adjustments for head size are required. Surgical techniques may need to be altered or adapted in special cases, such as Mondini malformation (cochlear malformation) or hearing loss due to meningitis with cochlear ossification. The surgeon may choose a specific technique that maximizes the likelihood of full implantation of the electrode array or use a special electrode array designed for severely ossified cochlea, depending on the degree of ossification. Cochlear implant surgery is done under general anesthesia and usually lasts 1 to 2 hours, and abroad it is usual to stay in the hospital for only one night after the surgery. However, in China, the post-operative hospitalization is longer. Although complications related to cochlear implants are rare, there are still some risks during the operation and the recovery period after the operation. With any surgery, general anesthesia always carries some risk, and there is the possibility of bleeding or infection in the immediate postoperative period, but both of these types of complications are very rare. A number of other complications are associated with ear surgery and they include facial nerve damage and postoperative vertigo. The approach of the implant to the inner ear requires passing through the facial recess, which allows the surgeon to maneuver very close to the facial nerve, but many other types of ear surgery utilize this approach with little risk of nerve injury. For those patients with anatomical malformations of the inner ear, such as Mondini’s malformation, the risk of facial nerve injury is somewhat greater. Although patients with inner ear malformations are potentially at risk for serious complications, meningitis is rare. The vestibular portion of the ear governs the balancing mechanism, and it is possible for it to remain functional when there is almost total loss of residual hearing, such that the opening of the inner ear for the purpose of implanting electrodes can cause a temporary imbalance. Although some adults and children report postoperative unsteadiness dizziness and nausea, it usually resolves quickly and is rare. In addition to the risks and complications associated with surgery and healing, there are some long-term risks. Although cochlear implants are designed to be reliable and have a lifelong lifespan, less than 2% of patients experience subsequent damage to their implanted device. Damage can manifest as a deterioration in hearing status or a complete lack of auditory stimulation. Once the damage has been confirmed by audiological and psychophysical measurements and a combination of multiple expert opinions, the device should be reimplanted. It is well documented that the results after reimplantation are often comparable to or better than those before reimplantation, and there have been some reports of deterioration after reimplantation, but they all seem to be related to structural abnormalities or some other complicating factors. A further complication is the gradual displacement or extrusion of the implanted device over time, which can be severe enough to require reimplantation. Although excessive displacement rarely occurs and only a few electrodes are displaced with little effect on hearing outcomes, displacement can be prevented by fixing the internal device by means of surgical techniques. The last possible complication is facial nerve irritation. This occurs most often in otosclerotic hearing impaired individuals or in patients whose anatomy predisposes them to electrical irritation of the facial nerve. However, the electrodes causing the problem can usually be turned off, so there is little or no negative effect.