Objectives: Cancer-related cognitive impairment (CRCI) is associated with adverse work-related outcomes in women living with a history of primary breast cancer. We explored the perceived impact of receiving adaptive cognitive training (dual nback training) or active control training (dual 1-back training) on CRCI. Furthermore, we explored the perceived transfer effects of cognitive training on workrelated self-management methods for cognitive impairment and work-related outcomes such as career development. Design: Longitudinal qualitative study. Methods: A 'framework' analysis approach was used to analyse semi-structured telephone interviews completed by women with a history of primary breast cancer before training (N = 40), one month (N = 30) and six months (N = 29) post-training. Results: Four main themes were identified: (1) impact of cognitive impairment at work, (2) perceived impact of cognitive training on impaired cognitive function, (3) perceived effects of training on work-related self-management methods for cognitive impairment and (4) perceived impact on women's career development and progression. Compared to baseline, women who received adaptive dual nback training reported sustained improvement in multiple cognitive domains including memory and attention up to six months post-training when the follow-up interviews were conducted. Perceived improvements in cognitive function were associated with greater self-confidence and better | 253 EXPERIENCES OF COGNITIVE TRAINING ON WORK emotional well-being in work. These improvements were found to lower dependency on self-management methods for cognitive impairment and enhance effectiveness as well as prompt career development or progression for many women. Although some findings of a similar nature were reported in the active control dual 1-back training group the perceived effects were more pronounced and consistent in the dual nback group. Conclusions: Adaptive cognitive training (dual nback training) improves perceived CRCI experienced by women in the workplace, enhancing their self-confidence and general emotional well-being. These perceived improvements, in turn, can decrease reliance on self-management methods for cognitive impairment and improve work efficiency and contribute to career development and progression.