The current study was conducted to estimate the effect of topical application of two different prophylactic pastes on color stability and surface roughness of resin composite restorative materials. In order to design this study a total of 180 resin composite specimens was prepared. The specimens were divided into two equal groups (n=90) according to types of nano-based resin composite tested i.e: nanofilled and nanohybrid resin composite. Each group was randomly subdivided in to three subgroups (n=30) according to the type of prophylactic paste applied i.e: no prophylactic paste MI Paste and MI Paste Plus. Then each subgroup was further subdivided into two classes (n=15) according to the immersion solution employed for specimens immersion i.e: artificial saliva or coffee.Disc shaped specimens of each type of resin composite material were fabricated using a split Teflon ring with centralized hole (5mm diameter and 2mm thickness). The resin composite was bulk packed into the prepared mold, and polymerized from both sides using a light emitting diode polymerizing unit according to the manufacturer instructions. No polishing of the specimens was done. The bottom surfaces were labeled with a marker. The specimens were randomly presented to one of three test groups according to the prophylactic pastes applied ; G1:- Specimens served as control group non coated with any remineralizing prophylactic paste, G2:- Specimens were coated with fluoride free remineralizing prophylactic paste, G3:- specimens were coated with fluoride containing remineralizing prophylactic paste. Then the specimens were stored in distilled water at 37 for 24 hours before immersion in the selected solutions. Then the specimens were stored in one of the two immersion solutions i.e.; artificial saliva or coffee for 24 hours.Color stability and surface roughness of the specimens were measured at the baseline, after surface treatment and after immersion using Spectrophotometer and Digital microscope respectively. The results were recorded, tabulated, calculated and statically analyzed.The results showed that, no statistically significant difference between nanofilled and nanohybrid resin composite on mean color change. Also, there was no statistically significant difference between specimens treated with fluoride free remineralizing prophylactic paste, specimens treated with fluoride containing remineralizing prophylactic paste and control specimens on mean color change values. The change in mean color values of the specimens following immersion in different solutions, showed that coffee recorded the statistically significant higher mean color change than artificial saliva.The results of mean surface roughness values of the two different resin composites tested showed that nanofilled resin composite had statistically significantly lower mean surface roughness values than nanohybrid composite.