In this paper, consideration has focused mainly on the extent and usefulness of the existing literature available so far on the understanding of the impact of climate change on water resources in Africa, focusing mainly on the Olifants River basin in South Africa. Here, the existing literature on the impact of climate change on the hydrological cycle (particularly the hydrological processes like temperature, precipitation and runoff) has been reviewed. The uncertainties, constraints and limitations in climate change research have been discussed at great length. A detailed discussion has been highlighted on the remaining knowledge gaps in climate change research, especially in Africa. In addition to the research gaps highlighted here, the emphasis on the need of climate change research by African scientists is included as part of lessons learnt. Overall, the importance of conducting further research in climate change, understanding the potential impact of climate change on our lives, and taking actions to effectively meet the adaptation needs of the people, emerge as an important theme in this review. (C) 2017 Elsevier Ltd. All rights reserved.