The effect of lime mud from paper-making process (LMP) addition on the H-2 fermentation of food waste (FW) was investigated. It was found that a slight addition of LMP (1.0-4.0 g in 200 g FW) significantly enhanced the H-2 fermentation performance, not only increasing the total amount of H-2 produced but also accelerating the whole reaction, shortening the lag period, and increasing the H-2 production rate. Fermentation stability and microbial germination were also facilitated by LMP addition. This was attributed to the existence of Ca, Fe, Mn and alkaline substances such as CaCO3 and NaOH. The batch process treating a mixture of FW and LMP was showed that the highest hydrogen production of 137.6 mL H-2/g VS was achieved at final pH 5.0, adding 3 g LMP (in 200 g FW) to the fermentation process, which lag-phase time was about 2.5 h. Crown Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.