Purpose: To explore the impacts of IT infrastructure flexibility components (connectivity, modularity, compatibility, and IT personnel flexibility) on IT-business strategic alignment using Luftman’s strategic alignment maturity model. Design/methodology/approach: A questionnaire was developed using 5-points Likert scale. The questionnaire was distributed to companies in Indonesia, where 48 companies filled the questionnaire completely. The data were analyzed using partial least squares (PLS) approach using WarpPLS version 3.0. Findings: This research found that amongst four components of IT infrastructure flexibility, only compatibility that gives a positive and significant impact to IT-business strategic alignment. This finding is remarkably in contrast to what had been found by Chung et al (2003) in which connectivity, modularity and IT personnel flexibility showed a positive impact on strategic alignment while compatibility did not. Research limitations: This research used small sample size. More respondents are required to obtain more general conclusions. Practical implications: The findings of this study can be input for IT investment initiatives by first focusing on compatibility aspect of IT infrastructure which is considered having the most significant influence on strategic alignment. Originality/value: Previous study investigated IT infrastructure flexibility as a single concept, whereas our research investigated the components of IT infrastructure flexibility and their impact on strategic alignment.