The main purpose of the study was to investigate relationships between perceived customerrnbehaviors (including customer participation, citizenship behavior, complaint behaviour, andrnmisbehavior) and frontline employee engagement (FEE) in employee of Commercial Bank ofrnEthiopia under Addis Ababa area zone. The population of this study was employees of CBE whornare working with various branches of the bank found in various geographical locations of AddisrnAbaba specifically from the four districts i.e. North, south, west and east of the bank, which haverngot 261 branches. The research is quantitative method and cross-sectional field survey and cornrelational study. By using Multi-stage sampling, 368 employees were selected as the sample ofrnthe study. The standardized measurement scales were adapted and distributed to 368 employeesrnin the form of questioners but, 341 respondents filled and replied were found valid for analyzed.rnA quantitative method which was cross-sectional study with deductive approach was chosen in thisrnresearch. The SPSS version 20.00 for windows was used to process the primary data which wasrncollected through questionnaire; a theoretical framework was used as a guideline to test thernrelationships between customer behavior and frontline employee engagement. Next, the researchrnpresents the research framework, methods, measures and findings and conclusion. Multiplernregression analysis assessed the impact of customer behavior on employee engagement. Resultsrnindicate the positive effects of customer participation and citizenship behaviour on FEE werernaccounted for by explained such behaviours. Customer complaint had poor negative effect onrnemployee engagement and customer misbehaviour also had positive insignificant effect on FEE.rnFindings highlighted the need for customer behaviour intervention to encourage theirrnparticipation and manage their complaint behaviours during service encounters. Implications forrnpractice are also discussed in the manager/supervisor development such as sensitivity trainingrnand workplace culture improvement to create the right environment for engagement