BIM can examine the placement of ductwork and machinery. It significantly increases the efficiency of a mechanical design. In addition, BIM functions as a database to simplify the use of simulation technology. It is important to know the expectations of mechanical engineers who will become frequent users of BIM in the future. A survey was conducted among Japanese mechanical engineers to analyze the expectations of mechanical design using BIM. The results show that many respondents strongly recognize BIM as a three-dimensional CAD program and expect not only the optimization of their design work but also to enhance design functionality.