Objectives This current study investigates the effect of lean management system on work attitudes of workers of two manufacturing companies. “Lean management” is a concept of work processes and human relations that determines company’s productivity and profitability. Workers of two enterprises, the first one with lean production and the second one with old mass production, were compared for their readiness for change and job satisfaction (both emotional and cognitive aspect). Materials and Methods The sample of 102 employees completed a battery of instruments such as: the Job Description Inventory by Neuberger and Allerbeck, the Job Affect Scale by Burke et al. and the Change-Readiness Scale by Kriegel and Brandt. Results: Individuals from the lean manufacturing company were characterized by higher level of readiness for change, positive affect at work, and cognitive job satisfaction. Conclusions In this approach the introduction of lean production positively affected company’s human resource attitudes.