Information systems development projects (ISDPs) often face requirements uncertainty. Thus, coping with this issue is an important project management task in ISDPs. In order to gain insights into which different requirements uncertainty situations exist and how to cope with them, we conducted a longitudinal interpretive case study. We investigated the requirements analysis of an ISDP in an international insurance company for 17 months. Thereby, we identified eight distinct requirements uncertainty situation types, observed ten requirements engineering (RE) techniques applied in practice and their impact on requirements uncertainty situation types, and finally derived recommendations for applying RE techniques in requirements uncertainty situations based on our observations. We combine these findings and contribute to RE literature by making a first step towards a framework for coping with requirements uncertainty in ISDPs. We believe that RE researchers as well as practitioners in ISDPs can make use of this article’s insights.