In construction project management, the significance of “lessons learned” (LL) is crucial for effective project management and continuous improvement. This study identifies nine values, seven enablers, and eight barriers to LL practices in the construction industry, based on insights from construction professionals in Malaysia. The aim is to highlight the importance of LL practices in improving project success and fostering a culture of ongoing enhancement. Key LL values include avoiding repeated mistakes, improving performance through past lessons, and promoting collaboration within project teams. By prioritising LL practices, organisations can optimise project outcomes, minimise rework and delays, and enhance future project planning and estimation. The study demonstrates that LL practices help prevent the recurrence of past mistakes and improve project performance. Enablers such as peer recognition, a sharing culture, and honouring commitments are vital for creating knowledge-sharing environments that support communication, collaboration, and trust. However, barriers such as interpersonal skill deficits, resource limitations, and varying levels of education and experience hinder LL implementation. Overcoming these barriers requires targeted interventions, including training and resource allocation. This study offers valuable theoretical and practical insights, providing strategies to enhance knowledge management systems, optimise project outcomes, and achieve sustained success in the competitive construction industry.