Construction sector in India has been on a high growth path lately and maximizing efficiency and profitability has been a key concern. Lean Construction offers a potential solution for system level efficiency improvement. Given the weak planning processes, diverse cultures and ill-trained labour in the industry, Lean implementation has been a challenge. IIT Madras, an educational institution, had recently taken up a carefully-structured programme for training and implementation of Lean construction practices in nine trial projects with varying characteristics through classroom and webinar-based trainings, reporting in predefined formats, monitoring by site visits and periodic reviews. Sites were encouraged to adopt the LPS as the core and use various other Lean tools with close assistance from the Faculty. Overall many of the standard benefits of Lean implementation were realised. However, the extent of gains was seen to be influenced by many soft aspects, such as the culture of the site and the organisation, planning and engineering expertise available, commitment and support from top management and site management. The paper presents an overview of the programme and an analysis of the results obtained/lessons learned across the different sites based on the organisational and cultural aspects of the sites.