Water-only cyclone (WOC) is an autogenous medium cyclone which performs a gravity separation using water as a separating fluid. Modified water-only cyclones (MWOC) are presently being used for fine coal cleaning in only two washeries in Turkey. In this study, MWOC was designed, installed via local facilities, and then implemented for the treatment of fine coal. The effects of the major parameters of MWOC, such as cyclone diameter, vortex finder diameter and apex diameter, on washing performance were investigated in detail. Then, the results obtained through the MWOC under optimum conditions were compared with those obtained through spiral and flotation. The tests show that the MWOC produced clean coal equal in quality to that produced by the spiral and flotation machine. However, the clean coal yield of the MWOC is quite a bit lower than that of the spiral and flotation machine, and the reject contains a significant amount of combustible matter. In summary, it was concluded that the MWOC can be used in washeries for pre-enrichment due to its simple structure, easy-control features and lower operational costs. (C) 2012 Elsevier B.V. All rights reserved.