The purpose of this study was to investigate the effect of stress induction on cognitive failure and working memory with regard to the role of cognitive flexibility. The study used a quasi-experimental design of pretest-posttest groups. The study population were female students who lived in dormitories of Imam Khomeini International University of Qazvin, which 100 of them selected by convenience sampling, and of these, 44 participants (22 participants with highly cognitive flexibility and 22 participants with lower cognitive flexibility) were entered into the final analysis. For data collection, Working Memory Test (Daneman & Carpenter, 1980), Cognitive Failures Questionnaire (Broadbent, Cooper, Fitzgeral & Parkes, 1982), and Cognitive Flexibility Questionnaire (Dennis & VanderWal, 2010) was used. The findings showed that after stress induction, there was a significant difference between the two groups with high cognitive flexibility and low cognitive flexibility in terms of performance of the mental processing part of working memory and three dimensions of cognitive failure including distraction, memory problems and action slips. However, under conditions of stress experience, there was no difference between the two groups in terms of mental storage and not remembering names. Therefore, it can be concluded that stress experiences affect mental processing of working memory and most dimensions of cognitive failures, but this is dependent on the level of cognitive flexibility.