A CAD database generated by an automatic schematic capture system needs to be verified before it can be used in design automation. This verification is best performed by a knowledge-based expert system. Presented is the design of a knowledge-based system for the verification of CAD database generated by AUTORED. A database-driven, pattern-direct inference technique is used to identify and correct erroneous data records due to misrecognition. This knowledge-based verification system has been implemented on a VAX 11/750 equipped with a video camera to read circuit diagrams into the computer. Integration of this verification system into AUTORED makes the automatically generated database accurate for design automation applications.