Deep brain stimulation of subcortical structures, such as the subthalamic nucleus, internal pallidum or ventral intermediate nucleus of the thalamus, are currently used for the treatment of advanced Parkinson's disease with motor fluctuations or during resistant tremor. This review discusses the various adverse events occurring with this surgery by focusing on each stage of the procedure and the various stimulated targets. Intraoperative complications are rare whichever technique or type of target is used. The most frequent postoperative side effects are observed during stimulation of the subthalamic nucleus. It is likely that the small size of the nucleus and the possible spreading of current to the surrounding functional areas contribute to this phenomenon. However, these side effects are generally mild and transient compared with the dramatic improvement in motor symptoms and fluctuations. Deep brain stimulation of the internal pallidum and thalamus are not effective on all the motor symptoms in Parkinson's disease but adverse effects appear less frequently. Whatever the target, intraoperative complications and secondary side effects are being reduced by the use of new neuroimaging technology associated with an accurate intraoperative neurophysiological investigation.