Cognitive adaptability has been conceptualised as the ability to effectively and appropriately change decision policies (i.e. to learn) given feedback (inputs) from the environmental context in which cognitive processing is embedded. Based on a large sample of 2650 established entrepreneurs in South Africa, this study attempts to determine how entrepreneurs cognitively adapt to unpredictable entrepreneurial environments. Multidimensional constructs representing cognitive adaptability and the Big Five personality traits were operationalised and empirically investigated. It was hypothesised that the Big Five personality trait dimensions of openness to experience, conscientiousness, extraversion and agreeableness are positively related to the cognitive adaptability dimensions of goal orientation, metacognitive knowledge, metacognitive experience, and metacognitive choice and monitoring. Neuroticism was hypthesised to be negatively related to the cognitive adaptability dimensions of goal orientation, metacognitive knowledge, metacognitive experience, metacognitive choice and monitoring. Hypotheses were tested using structured equation modelling and correlational and regression analysis. Results provide support for subcomponents of the Big Five personality traits. Intellectual interest (openness to experience), goal striving (conscientiousness), activity (extraversion), prosocial orientation (agreeableness) were found to be positively related to cognitive adaptability. They were found to be negatively related to prior metacognitive knowledge. Self-reproach (neuroticism) was found to be negatively related to cognitive adaptability. It was found to be positively related to prior metacognitive knowledge. This research builds on and extends existing literature on cognitive adaptability in an entrepreneurial context by bringing together two streams of literature from psychology metacognition and personality traits. The implications of the process for dynamic, adaptable thinking are important in an emerging context such as that found in South Africa. The results of this study will inform the practice of policy makers who are trying to encourage start-up entrepreneurs to think about thinking in unpredictable entrepreneurial environments. In terms of methodology, the use of a sample of established entrepreneurs is desirable for this type of research since metacognition is better studied in entrepreneurs who are involved in a series of activities. / Thesis (PhD)--University of Pretoria, 2016. / Business Management / PhD / Unrestricted