BackgroundThe lack of appropriate vaccines is an obstacle to the effective management ofA. baumanniiinfections. Peptide vaccines offer an attractive and promising preventive strategy againstA. baumannii.ObjectiveIn this study, we identified specific T cell epitopes ofA. baumanniiouter membrane protein K (OMPK) using comprehensive bioinformatics and detailed molecular docking analysis.MethodsBoth class-I and class-II T cell epitopes ofA. baumanniiOMPK were predicted by three tools namely IEDB, SYFPEITHI, and ProPred. The predicted epitopes were shortlisted based on several analyses including prediction scoring, clustering, exclusion of human similarity, considering immunogenicity and cytokine production, and removal of toxic and/or allergen epitopes. The epitopic peptides with high prediction scores and appropriate properties containing both class-I and class-II T cell epitopes were selected. Two of these class I/II epitopic peptides were chosen for molecular docking studies and assessing their physicochemical properties as vaccine candidates.ResultsThe results showed many T-cell epitopes of OMPK that could be evaluated for possible immunogenicity. Two of these epitopes (containing both class-I and II epitopes) had high prediction scores, were predicted by several tools, attached to several HLAs, and had the best docking score. They had different physicochemical properties and were conserved among Acinetobacter species.DiscussionWe identified theA. baumanniiOMPK high immunogenic class-I and class-II T cell epitopes and introduced two promising high immunogenic peptides as vaccine candidates. It is recommended to perform in vitro/in vivo investigation of these peptides to determine their true efficacy and efficiency.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13104-023-06409-9.