© 2016 Australian Society of EndodontologyThe aim of this study was to evaluate tooth discoloration after the use of root canal sealers and the effect of internal bleaching on sealer discoloration. The crowns of 56 incisors were cut and randomly filled with four sealers (n = 14): Pulpispad, AH26, MTA Fillapex, EndoREZ. The colour measurement was taken with a spectrophotometer prior and after placement of sealers. Colour changes (ΔE) were recorded after 4 weeks then sealers were removed and an internal bleaching treatment was performed. After bleaching treatment colour changes (ΔE) were measured. Data were analysed using ANOVA and Tukey’s test (α = 0.05). All tested sealers induced varying chromatic alterations. Pulpispad showed statistically more discoloration than other sealers (P < 0.05). After bleaching, EndoREZ showed statistically more bleaching ratio than MTA Fillapex and AH26 (P < 0.05). Internal bleaching was efficient in discoloured teeth induced by root canal sealers.