This paper presents a novel effective method for the optimization of oil agglomeration process of Zonguldak/Turkey bituminous coal with multiple performance characteristics based on the grey relational analysis (GRA). Oil agglomeration parameters including solid content, amount of oil, agitation time and agitation rate were optimized based on multiple performance characteristics. The characteristics of interest are the grade and the recovery of the agglomerates. Nine experiments were conducted using GRA to optimize the settings for oil agglomeration parameters to generate various quality characteristics. Analysis of the grey relational grade indicates the parameter significance and the optimal parameter combination for the oil agglomeration process. The analytical results from two confirmation experiments using the optimal parameters confirm that the above performance characteristics in oil agglomeration process can be improved effectively through this approach. (C) 2013 Elsevier Ltd. All rights reserved.