Chicken feathers are the most abundant keratinous biomass in the world. Disposal of the huge and increasing volume of waste feathers presents as a major concern for poultry industry. On the other hand, energy and material recovery of this valuable protein source is an important issue for organic solid waste treatment and bioenergy generation. Anaerobic digestion is an environmentally and economically promising alternative process for biogas production of waste feathers. In this study in order to enhance the methane potential of batch anaerobic digestion of chicken feathers this waste was treated by various kinds of pretreatments including thermal, thermo-chemical, enzymatic, thermo-enzymatic and chemo-enzymatic methods. Also the effect of different treatment conditions on the methane yield was investigated. As a whole, thermo-chemical pretreatment with lime (Ca(OH)2) rendered the most significant effect on enhancement of the chicken feathers methane potential. In particular lime treated triplicate samples under treatment condition of 40g TS feather/l water, 0.1g Ca (OH)2 /g TS feather, 100°C and 30 min produced the highest amount of methane (an average maximum volume of 480 Nml/g VS, which is about 96.8% of the theoretical methane potential of protein), during 50 days of anaerobic incubation. Increasing the operational parameters such as feather concentration, lime loading, temperature and reaction time improved the feathers solublisation resulting in a higher soluble chemical oxygen demand (SCOD) concentration of the samples but inserted negative impacts on the anaerobic digestion performance. Although other pretreatment methods improved the SCOD concentrations of the feathers too, compared to the lime treatment those methods didn’t show considerable effects on the enhancement of methane yield from the chicken feathers. Thermo-enzymatic, enzymatic, and thermal pretreated triplicate samples produced an average maximum of 185 Nml/g VS, 154 Nml/g VS, and 143 Nml/g VS (37.3%, 31%, 28.8% of the theoretical methane potential) respectively, during 33 days of 50 days of anaerobic incubation. Especially, chemo-enzymatic pretreated sample showed negative methane potential of only 41 Nml/g VS, i.e. 8% of the theoretical methane potential. Consequently, lime pretreatment under the above recommended conditions can be suggested for hydrolysis of chicken feathers to achieve significant enhancement of its methane potential.