Purpose The purpose of this study is to determine the effect of conscientiousness and extraversion personality traits on project success. The relationship is mediated by affective professional commitment, whilst the relationship between personality traits and project success is moderated by organizational project management maturity. Design/methodology/approach The deductive approach is used to achieve the objectives of this study. Data were collected through a purposive sampling technique from 250 respondents with the help of questionnaires from information technology sectors. The structural equation modelling (SEM) in partial least squares-SEM and SPSS is used to analyse the data and to examine the hypothesis. Findings The outcomes demonstrate the partial mediating impact of affective professional commitment between the relationship of conscientiousness and extraversion personalities with project success. Additionally, it proves the moderating effects of project management maturity between the relationship of conscientiousness and extraversion personalities with project success. Practical implications This study reflects that employee personality appears to be a reliable indicator of how an employee is faithful to his profession. This faithfulness or duty decides the employee’s execution in terms of offering a successful project. Thus, achieving employee commitment needs to be done by completing the project successfully by the organizations in the presence of project management maturity systems. Originality/value It is the first study of its kind to provide experimental proof of the impact of a manager’s personality traits on project success in the presence of affective professional commitment (mediator) and organizational project management maturity (moderator).