Aim of this paper is to compare the new polysomnography staging manual according to American Academy of Sleep Medicine with Rechtschaffen & Kales rules, underlying the newly introduced aspects and illustrated with polysomnographic images. The new rules simplify the staging but increase the time of electrodes application. They were established on the base of low levels of evidence, without being included in the multicenter statistical validation. For the first time in literature are given details about the criteria for the interpretation of sleep in children, but there are problems still remain unanswered, such as those regarding the scoring of hypopnea. In Romania, the main problem is primarily limited access to investigation and the deficit of health professionals.