The issue of Waste from Electrical and Electronic Equipment (WEEE) in Africa lacks a concrete answer at present. This study aimed to provide an integrated approach using qualitative and quantitative research methods based on the 80/20 principle and the grey system theory, in order to address the uncertainty in the existing literature. First, through a qualitative approach, the authors analysed the environment for the management of WEEE by eight companies in Cameroon, through a literature review and observations made in the field under the framework of the ISO 14001:2015 standard. Then, the weights of the selected cause of the WEEE using grey system theory were proposed and applied, combining the findings from both the qualitative and quantitative methods. Based on the data obtained through the analysis, the research results indicate that the assessed Cameroonian companies dealing with WEEE management can implement measures to reduce WEEE.