Cognitive failures at work (or errors in the workplace including blunders and memory lapses), can lead to considerable personal and organisational damage, even damage well beyond national borders in some organisations. Workplace errors may have a personality base; and mindfulness (or mindlessness) also appears to be related to workplace errors generally. Given the importance and cost of errors in the workplace it is of concern that no previous research appears to have addressed the relationships between cognitive failures at work, personality and mindfulness together. We aimed to address this gap. We administered the Cognitive Failures Questionnaire, the Mindful Attention Awareness Scale (MAAS) and the Big Five International Personality Item Pool 50-item questionnaire (IPIP) to a sample of 92 Australian-based employees from a variety of organisations. Our results showed workplace errors (including lapses in general memory, blunders, distractions and recall of names) were related to lower levels of mindfulness and to lower levels of emotional stability (that is, the other end of the neuroticism- emotional stability continuum). Extraversion was associated with not making blunders, but the other three factors of the Big Five (Openness, Agreeableness, Conscientiousness) were not found to be related to workplace errors. These results demonstrate important relationships between mindfulness and workplace errors; and personality (mainly Neuroticism- Emotional Stability) and workplace errors. Giving special attention to mindfulness training and to effective mental health training in organisations is recommended, especially where lapses in attention or workplace actions can lead to costly personal and organisational mistakes.