A uniformly coated MoS₂/carbon-nanocomposite with a three-dimensional hierarchical architecture based on carbonized bacterial cellulose (CBC) nanofibers is synthesized by a facile one-step hydrothermal method followed by thermal annealing at 700 °C in an Ar atmosphere. Strong hydrogen bonds between the Mo precursor and the BC nanofibers are found to be crucial for the in situ growth of MoS₂ nanosheets on the nanofibers during the hydrothermal process. The fibrous structure was maintained and the connection between MoS₂ and the nanofibers were strengthened in the sintering process, leading to an improved stability of the resulting nanocomposite upon electrochemical cycling. The low-cost and environmentally friendly 3D web-like structure enables binder-free and carbon-free electrodes for lithium-ion batteries, which exhibit high specific discharge capacities up to 1140 mA h g^-1 at the C-rate of 1C without significant capacity fading for over 50 cycles. The porous conductive hierarchical structure of the composite endows excellent rate performance by avoiding the aggregation of the MoS₂ nanosheets and by accommodating mechanical stress which appears upon electrochemical cycling.