This study focuses on how valid information about learner perception of strategy use during communicative tasks can be gathered systematically from English as a foreign language (EFL) learners. First, the study attempted to develop a questionnaire for statistical analysis, named the Oral Communication Strategy Inventory (OCSI). The research project consisted of 3 stages: an open-ended questionnaire to identify learners' general perceptions of strategies for oral interaction ("N" = 80); a pilot factor analysis for selecting test items ("N" = 400); and a final factor analysis to obtain a stable self-reported instrument ("N" = 400). The resulting OCSI includes 8 categories of strategies for coping with speaking problems and 7 categories for coping with listening problems during communication. The applicability of the survey instrument was subsequently examined in a simulated communicative test for EFL students ("N" = 62). To validate the use of the instrument, participant reports on the Strategy Inventory for Language Learning (SILL) were compared with the result of the OCSI. When combined with the oral test scores, it was revealed that students with high oral proficiency tended to use specific strategies, such as social affective strategies, fluency-oriented strategies, and negotiation of meaning.