Objectives The aim of this in vitro study was to evaluate the effects of five different two-step diamond impregnated polishing systems (Sof-Lex Spiral, Venus Supra, Komet Spiral, CompoMaster and Shapeguard) on the surface roughness and morphology of a submicron hybrid composite resin material (Brilliant Everglow).Materials and methods Two-hundred composite resin discs were prepared with 180 SiC paper to produce a uniform baseline surface. The samples were randomly assigned to one of five groups and polishing was completed by one operator. The arithmetic mean surface roughness (Ra) was measured using contact profilometry and the surfaces were examined under an SEM.Results Statistical differences (p <0.05) were identified between the surface roughness remaining after use of the polishers. Diatech Shapeguard (0.22 μm, SD 0.08) and Komet Spiral (0.26 μm, SD 0.09) polishers yielded the lowest Ra values, while the CompoMaster polishing system led to the highest surface roughness values (0.55 μm, SD 0.19).Conclusions Within the limits of this in vitro study of the efficacy of diamond impregnated two-step polishing systems, Diatech Shapeguard and Komet Spiral polishing systems produced the lowest surface roughness values. These polishing systems yielded acceptable surface roughness values with regards to oral health and patient comfort.Clinical relevance Similarly designed polishing systems do not produce comparable surface roughness levels and clinicians should be aware of this when considering polishing protocols for composite restorations.