Design of a die casting die is a nontrivial task, which depends upon a number of influencing factors related to material, part geometry, manufacturing resources, cost, delivery time, etc. Complexity of this die design activity further increases in case of a multicavity die. Currently available die design systems lack in the level of automation and do not explicitly address multicavity die design. Present work is an attempt to develop a system, which facilitates computer-aided design of a multicavity die casting die. The objective of the proposed system is to automate the process of deciding number of cavities, design of cavity layout and die-base, and core and cavity creation for a multicavity die casting die. The proposed system, which we named Auto_Die_Caster, works as an add-on application to solid modeling software SolidWorks. The proposed system is divided into four modules, namely data initialization, cavity design, cavity layout and die-base design, and core-cavity design. Use of commercial software like SolidWorks as a platform both for part design and generation of die design eliminates loss of data which makes the proposed system quite useful in the industrial scenario. To demonstrate the capabilities of Auto_Die_Caster, it was tried for a number of die casting parts and the results are presented. Proposed system is a step forward to design manufacturing integration for die casting process.