Lean is a business process transformation approach that eliminates ‘wastes’ – activities that generate no value for the customer. Lean originated from the production line but is widely implemented in the service sector. This study investigates human and social factors in a Lean transformation in a ‘knowledge worker’ environment. We identify a paradox: a successful Lean programme in the service sector develops staff who are educated and empowered and thus potential opponents to future business change. We offer five recommendations for organizations undertaking Lean transformations: (1) Build an in-house organization-wide ‘Lean Team’ to drive the programme rather than hiring external consultants; (2) Ensure participation is recognized and rewarded; (3) Replace departmental parochialism with a genuinely corporate vision; (4) Align the Lean programme with corporate information strategies; (5) Incorporate Lean thinking into the organizational culture.