Although lean construction is now widely known and practiced by contractors in the developed world, contractors in developing countries such as South Africa are either unaware of it or just beginning its implementation. However, the application of lean construction practices is reported to occur with a gap between training/teaching and the actual reality of a company. To bridge this gap, a lean opportunity assessment (LOA) is usually used as a start. This paper is about LOA that was conducted among five contractors in the Free State province of South Africa. The aim of the multiple case study research design was to perform the LOA so that areas in which lean practices are in need of enhancement can be established and motivated. The study adopted an LOA protocol from the 'lean supply chain and logistics management' book by Paul Myerson and then conduct further interviews to obtain more views on the LOA variables. The variables include internal communication, visualisation and workplace organisation, operative flexibility, continuous improvement, mistake proofing, quick changeover, quality of inbound and outbound materials, supply chain, balanced flow of work, total productive maintenance (TPM), pulling tasks on site, and standardized work. The data suggest that the five contractors have to address weak continuous improvement, physical construction activities, mistake proofing, and performance measurement practices in their companies.