A single case-study design approach was implemented in this qualitative study of 13 participants to identify critical success factors that influence project success in bespoke turnkey mechanical engineering projects within a project-based organisation. Using Nvivo and thematic analysis the study revealed important project success factors. The findings confirm the previous research and extend our understanding of turnkey projects by introducing additional factors such as avoidance of multitasking, availability of materials, and cost-effectiveness of work. A competent project manager with strong leadership skills was also found to be essential for setting clear goals, managing resources, avoiding multitasking, and ensuring a motivated team that cooperates and takes responsibility for results. Establishing realistic project plans, working cost-effectively, and implementing procurement and supply chain strategies were identified as critical elements in ensuring material availability to complete the project, resulting in the timely delivery of a quality product within budget. None of this would be possible without effective communication that ensures accurate information is communicated to the right project stakeholders.