One of the most important sectors in infrastructure development in Laos is road construction. However, many road construction projects in Laos suffer from extensive delays. This causes damage such as recurring problems in the road construction industry, and has a negative effect on the success of road construction projects in terms of schedule, cost, quality, safety and the amenity of road users. The goal of this study is to determine the main causes of these delays and to offer remedies. To identify the causes of delays, a questionnaire is designed by modifying one used to measure causes of delays in road construction projects in the West Bank in Palestine and in consultation with engineering experts with more than 10 years of experience in Laos road construction projects. A total of 53 causes of delay are identified as important in Laos. Questionnaire respondents included 35 contractors, 31 owners and 24 consultants in total. The survey results indicate that the five top factors causing road construction delays are: Contractor cash flow; Delayed payment by owner; Difficulties in financing project by contractor; Financial issues related to owner; and Insufficient equipment and vehicles for the work.