Workplace based assessments (WBAs) are now commonplace in postgraduate medical training. User acceptability and engagement is essential to the success of any medical education innovation. To this end, possessing an insight into trainee and trainer perceptions towards WBAs will help identify the major problems, permitting strategies to be introduced to improve WBA implementation. A review of literature was performed to identify studies examining trainee and trainer perceptions towards WBAs. Studies were excluded if non-English or sampling a non-medical/dental population. The identified literature was synthesised for the purpose of this critical narrative review. It is clear that there is widespread negativity towards WBAs in the workplace. This has negatively impacted on the effectiveness of WBA tools as learning aids. This negativity exists in trainees but also to an extent in their trainers. Insight gained from the literature reveals three dominant problems with WBA implementation: poor understanding as to the purpose of WBAs; insufficient time available for undertaking these assessments; and inadequate training of trainers. Approaches to addressing these three problems with WBA implementation are discussed. It is likely that a variety of solutions will be required. The prevalence of negativity towards WBAs is substantial in both trainees and trainers, eroding the effectiveness of learning that is consequent upon them. The educational community must now listen to the concerns being raised by the users and consider the range of strategies being proposed to improve the experiences of trainees, and their trainers.