IntroductionWorkplace bullying (WPB) among trainee doctors is a concerning problem in Malaysia. However, there is still limited understanding regarding the influence of trainee doctors’ personality traits on WPB. Furthermore, the impact of contract employment status on WPB among trainee doctors is not yet well-defined. To address these gaps, this study was aimed to determine the prevalence of WPB among trainee doctors and to examine the association of sociodemographic characteristics, job characteristics, and personality traits with WPB among trainee doctors in Malaysia. MethodsA multi-center cross-sectional study was conducted with 264 trainee doctors in Selangor, Malaysia. Eligible participants were provided with sociodemographic characteristics questionnaire, job characteristics questionnaire, WPB questionnaire, and the Big Five Inventory-10 (BFI-10). Chi-square tests were used to examine the association between: (i) sociodemographic characteristics and WPB, (ii) job characteristics and WPB; and (iii) personality traits and WPB. Multivariate logistic regression was performed to evaluate the association between the significant independent variables (as determined from Chi-square tests) and WPB. ResultsThe prevalence of WPB was 45.1 %, with verbal abuse being the most common form of bullying (46.2 %). Chi-square test showed that only marital status and low agreeableness were significantly associated with WPB. Subsequently, multiple logistic regression demonstrated that being married (OR: 1.866; 95 % CI: 1.077–3.234) and low agreeableness (OR: 2.287; 95 % CI: 1.169–4.473) were significant predictors of WPB. ConclusionThe high prevalence of WPB among trainee doctors could be attributed by marriage and low agreeableness personality traits in this population. In order to minimise WPB and maximise workforce potential, it is essential for healthcare institutions and medical training programmes to recognise this vulnerabilities and take steps to protect and support trainee doctors who are married and/or with low agreeableness personality trait.