BACKGROUND Sleep movement disorders includes mainly periodic limb movement and others. The more frequent breathing disorders are: obstructive sleep apnea-hypopnea syndrome and primary snoring. OBJECTIVE To compare sleep architecture in periodic limb movements and breathing disorders of different severity, and weight their interactions. METHODS We compared sleep architecture in 160 patients, divided in six groups: periodic limb movements (n=25), obstructive apnea only (n=30), periodic limb movements/snoring (n=30), periodic limb movements/mild apnea (n=25), periodic limb movements/moderate apnea (n=25), periodic limb movements/severe apnea (n=26). Polysomnographic variables were compared by analysis of variance and Tukey test. RESULTS We observed an increase of percentage of awakenings in the group with periodic limb movements/severe apnea. We found an increase of percentage of light sleep in the group with obstructive apnea only with respect to periodic limb movements group. The group with obstructive apnea only presented less rapid eye movements sleep in relation with group with periodic limb movements. We found an increase of awakenings in the group with periodic limb movements/severe apnea to the group with periodic limb movements only. Oxygen saturation showed a decrease in the group with periodic limb movements/severe apnea and obstructive apnea only group to periodic limb movements only group. CONCLUSIONS Periodic limb movements and breathing disorders, resulted in more additive changes in sleep architecture alterations, than as separately disorders, in a complex interaction. Research in these relations deserve more investigations.