This study seeks a robust design of square-to-box rolling that leads to minimum variation in the geometric profile of rolled workpieces. Variations considered are the workpiece geometry, the roll diameter, and roll gap. The paper focuses on the variation of the workpiece width. The key is to define parameters that correctly reflect the physical characteristics of shape rolling. The study applies the Taguchi method to finite element simulation of rolling process using seven design and process parameters. Sensitivity analysis and comparison with empirical knowledge lead to design guidelines that reduce lateral spread variation in the square-to-box roll pass process.