Sustainability is considered to be a central part of every global policy change because of the likelihood of negative effects of particular policies on the already endangered environment and on society. Whilst sustainability is receiving significant attention in construction sectors in developed countries, this seems to be less true for developing countries. Thus, this study explores the challenges faced by the construction sector in one such developing country, Libya, in integrating sustainability practices into its common scope of activities. The study adopted a mixed research approach consisting of a questionnaire survey and expert interviews. Completed questionnaires (134 No.) were analysed using statistical techniques. The findings from the survey informed the topics for the interviews with 10 experts where the collected data were analysed through content analysis. The outcomes of the research explained that the awareness of sustainability in construction was weak in the practice of the Libyan construction sector. Additionally, the failure of supporting institutions to create an effective application of sustainability guidelines, lack of stricter legislation, building codes or standards were also found to be major challenges. The study contributed to knowledge by providing a better understanding of sustainability and clarified the main challenges faced by the stakeholders and which they have to consider in order to improve sustainable construction in Libya. The practical implications of the study include the strategies identified to avoid or minimise the challenges and their consequences.