Requirements Engineering (RE) activities require intensive communication among different stakeholders and an understanding of their behaviour in order to accurately identify requirements. As RE requires intensive communication, an individual's culture might influence RE activities. Thus, cultural influences affecting RE activities might need to be considered to improve RE activities and prevent issues that might affect software project outcomes. In our work, we propose a framework for identifying cultural factors that could influence RE activities. In this paper, we present the preliminary results of a case study conducted with Vietnamese practitioners.