Statement of problem: ceramic veneers are used to restore deep discolorations or spaced dentition. However, influence of routine of oral hygiene on color stability of ceramic veneers remains unknown. Purpose: The purpose of this in vivo study was to evaluate the impact of different mouth washes and tooth brushing techniques on color stability of ceramic veneers. Methods: 30 University Patients were selected to have Zirconia-containing lithium silicate ceramic veneer (ZLS) (celtra Duo) then were randomly divided into 3 groups 10 for each group (n= 10) , as follows: Group 1 participants were instructed to swish with water (control group) ,Group 2 instructed to swish with chlorhexidine based mouthwash(Hexitol). Group 3: instructed to swish with Alcohol based mouthwash (Tantum Verde). each of which included five people who either did powered (N = 5) or manual (N = 5) tooth brushing for 12 months on a daily basis .The color of the ceramic veneers was examined with Easy Shade following veneer cementation and then compared to subsequent readings at 6 and 12 months. In this study, Kruskal-Wallis test was used to compare the three groups in each duration independently. Results: Group 2 showed highly significant change when compared with group 3 &group 1. There was no significant difference between subgroups (A) used manual brushes& subgroups (B) used powered brushes in the same group for each duration months Conclusion: The chlorhexidine based mouthwash &Alcohol based mouthwash affected the color stability of Zirconia-containing lithium silicate ceramic veneer (ZLS).