The purpose of this study was to investigate the effect of three different ligation designs of self-ligating orthodontic bracket systems (SLBs) on friction, under wet and dry conditions. Universal testing machine was used to slide forty brackets of four different bracket types (twenty passive self-ligating brackets PSLBs, ten active self-ligating brackets ASLB, and ten preadjusted brackets with conventional elastomeric O-ties) along 0.019×0.025 stainless steel (SS) wire segments at crosshead speed 8mm/min. Testing was done under dry and wet conditions. Statistical analysis of collected data revealed that all three tested SLB types displayed significantly lower frictional forces (FF) than conventional brackets with conventional elastomeric O-ties (CEL) under both dry and wet conditions. Both tested PSLB types displayed significantly lower frictional forces than tested ASLB type, under both dry and wet conditions.