Project delays adversely affect road infrastructure development in developing countries. Unfavorable consequences of project delays involve cost overrun, contractual disputes, arbitration, and quality non-conformities. Despite these risks, literature shows that delays are still a prevalent problem in construction management. Although there is a considerable number of publications on project delays, few studies have compared their causes between developing countries. Therefore, this study aimed to: a) classify and determine the level of influence of the delay causes; b) find the relationship between delay causes and country's development; and c) propose recommendations for mitigating the most critical causes in developing countries. A systematic literature review provided a sample of 14 primary studies from Africa (50%) and Asia (50%). Based on this sample, the study found that developing countries, with a GDP per capita ($US2018) <= $ 2,000, may experience different delay causes depending on the economic and the geographical contexts. In African countries with a Global Competitiveness Index -GCI <= 56, road projects may experience delays due to financial issues of the project owner, and delays due to equipment/material issues of the project supplier/subcontractor. On the other hand, in Asian countries with a GCI between 62 and 49, road projects may experience delays due to financial issues of the project contractor, and delays due to planning issues of the project designer/consultant. According to these economic contexts, this study proposes a frame of causes and mitigation actions as a contribution to the risk analysis of road projects in developing countries.