Purpose: The main propose of this study is determining appropriate knowledge acquisition techniques to extracttunnel expert’s knowledge.Design/methodology/approach: A porposive sampling method was used and data were collected viaface-to-face interview based on a validated Knowledge Acquisition Questionnaire (KAQ). A total of 33 expertsin tunnel industry who were presented by Iranian Tunnel Associated were identified and selected.Findings: The result of this study showed that semi-structured interview, timeline, think aloud problem-solving,commentary, teach back, concept map, process map, repertory grid technique, composition ladder, decisionladder, process ladder interview, matrix, Observational techniques have meaningful effects on elicitation oftunnel experts’ knowledge.Limitation: Briefly, problem of this project were large number of experts, Limited time for interviews, (Inaccordance to these experts’ avocations and huge responsibility), and outspread geographical distribution (fromTehran, Khorasan, Khoozestan). Inadequate many experts know little about KM and it's advantagesOriginality/value: The innovation of this research is the first time this kind of research has been done in Iran.Until now, in Iran any working has not been done in the field of management and extraction knowledge experts.