Newer materials with excellent properties are of recent interest in the optical, electrical and electronics industries. Finishing of new materials for the required stringent specification stated by those industrial applications emerges the innovation of new techniques and processes in the field of manufacturing. Electrolytic in-process dressing (ELID) is one of those new manufacturing techniques which may produce mirror surface finish on various optical and non-optical materials. The easy implementation and the efficiency of the ELID technique have been drawing the attention of the optical manufacturing industries in the recent years. However, further improvements are essential in order to minimize the difficulties experienced during implementation and to extend its suitability for future applications. The authors propose a knowledge based feed-back control system for ELID grinding to eliminate the application difficulties and to improve the effectiveness of the process. This study aims to experiment and to analyze the various features of the developed feed-back control system. The main objective is to examine the effectiveness of the system for precision finishing of optical and non-optical harder materials. The possibilities to reduce the geometrical inaccuracies of the workpiece have been examined in this study. The results show that application of the feed-back control system minimizes the number of correction cycles necessary for precision finishing of hard materials, such as, quartz. © 2009 Elsevier Inc. All rights reserved.