PurposeIn most developing countries, indigenous emerging construction contractors (ECCs) face severe problems of not adopting a project management framework (PMF) in their business activities. It has increased their business risk and threatened their sustainability. Studies showed that government policy support (GPS) helps mitigate business risks. Thus, there is a paucity of literature concerning GPS on emerging Nigerian construction contractors' business sustainability. Therefore, the paper aims to investigate the moderating effect of GPS on the relationship between PMF and ECCs in Nigeria.Design/methodology/approachSmartPLS was used to analyse the collected data from the useable 310 questionnaires retrieved from respondents in Abuja and Lagos, Nigeria. Systems Theory was used to support the developed framework.FindingsFindings show that government policy support significantly moderates the relationships between PMF and ECCs in the Nigerian construction sector. It implies that the study's results offer more understanding regarding issues affecting construction entrepreneurs' sustainable business cycle via applying PMF to mitigate business sustainable associated risks.Practical implicationsThe study will stir Nigeria's ECCs and policymakers to promote construction business sustainability for a new entrepreneur, emphasising business risk management via PMF and GPS to enhance the sustainable business cycle.Originality/valueThe research (PMF and GPS) is strategies to enhance ECCs business sustainability in the Nigerian construction sector and other developing countries with similar political and economic attributes. Besides the study guiding old and intending ECCs and policymakers in the developing countries industries, it would contribute to bridge the theoretical gap regarding PMF and ECC, especially ECCs in developing countries with similar business sustainability issues.