This study investigates learners’ perception on the Flow State within a high-stakes EFL military instructional context. Thirty military personnel, including commissioned and non-commissioned officers, participated in a 12-week English immersion program. To explore learners’ experiential engagement during speaking-focused instruction, a mixed-methods design was employed. Quantitative data were collected through a Flow State Questionnaire, measuring nine core dimensions of flow. Complementary qualitative data were obtained from an open-ended survey in which participants reflected on their immersion during classroom activities. Descriptive statistics revealed that Clear Goals, Unambiguous Feedback, and Autotelic Experience were the most positively perceived dimensions, while Intense Concentration and Transformation of Time received the lowest mean ratings. Thematic analysis of the open-ended responses indicated that interactive discussions on personally meaningful topics facilitated cognitive and emotional engagement, whereas performance pressure, external administrative factors, and limited opportunities for informal interaction hindered flow. These findings suggest that learners’ immersion is unevenly distributed across flow dimensions. Based on these results, pedagogical implications are proposed to support more immersive and cognitively engaging task design in military EFL settings.