Fermentative bio-H2 production potential (BHP) of leather and municipal solid wastes was evaluated with varying range of C/N ratios (5 to 30) and organic loading rate (5 to 15 g.L-1.d-1) using mesophilic batch and CSTR reactors. The study concludes an optimum pre-treatment for hydrogenic seed inocula. The ascending percentage of H2 was linear (r2= 0.74) with increasing C/N ratio, decreasing NH3-N level and maximum BHP was recorded at C/N ratio of 30 and OLR of 15. The high difference in pH between total to soluble digestate at C/N ratio of 30 was consistent with high volatile organic acids (VFA), contributing H2 production. The high OLR (15gm.L-1.d-1) with short HRT (5days) resulted to pH between 5.5 and 6.5, favours high percentage of H2. The volatile solids (VS) removal and H2 yield was observed to be in the range of 12 to 58% and 0.08 to 0.38 Nm L.L 1of reactor volume per day. The high percentage of H2 (26%) was corroborated well with already reported study for MSW with slaughter house solid wastes.The high Adenosine tri phosphate (ATP) level in the digester was coincided well with high H2 yield and confirms ATP an alternate and rapid method to replace or augment the traditional volatile suspended solids (VSS) measurement as biomass activity of high solids anaerobic digesters. The study estimated fermentative H2 energy potential as kW/tonne of leather and municipal solid wastes, at an optimum C/N ratio, pH and OLR, producing H2 fuel cell as a source of clean energy.