Studies of lean production's effect on working conditions are mixed but point toward worsened conditions. The aim of this longitudinal study was to assess how lean contributes to transforming work characteristics in a medium‐sized specialized industrial family business. A mixed methods approach was used to combine an external assessment of work characteristics with self‐reported employee questionnaires. Favorable psychosocial working conditions were indicated, with role conflicts decreasing over time. The assessment of work provided descriptions of how lean practices contributed to decreased task control due to standardized work and simplified work processes. At the same time, employees still had opportunities to influence their long‐term work assignment. There was also a trend toward job enlargement through new, higher‐skilled tasks, multiskilling, and extended opportunities to influence work through different continuous improvement activities. The participative lean approach and type of skilled jobs may have contributed to this transformation.