Objectives: The aim of this in vitro study was to evaluate the affect of pre-heating on color stability of a microhybrid composite resin Materials and Methods: In this study an A1 shade microhybrid resin composite (Filtek Z250, 3M ESPE) was used after storage in 4 different temperatures (4°C, 23 °C, 37 °C, 55 °C). Forty discshaped specimens were prepared in a teflon mold with a diameter of 10 mm and a depth of 2 mm (n=10). In the first group the specimens were stored in refrigerator at 4 °C and the 2nd group were kept in room temprature at 23 °C. In the 3rd and 4th groups a composite warmer (Micerium, S.p.a., Avegno GE, Italy) were used for heating the tubes up to 37 °C and 55 °C, respectively. The specimens were light cured for 40 s with a quarts tungsten halogen curing unit (Smart-Lite, Benlioglu Dental, Ankara, Turkey). The baseline and after 48 hours storage in the coffee solution (Nescafe Classic) the color measurements of the specimens were detected with Vita Easy-Shade digital colorimeter device and δE were calculated. The data were analysed with parametric one-way ANOVA and Tukey HSD tests. Results: The composite group pre-heated to 37 °C and 55 °C showed significantly lower δE values than the groups at 4 °C ve 23 °C (p<0.01). Conclusion: Pre-heating of the microhibrit composite caused lower discoloration.