In this study, a methodology for electrodeposition of nickel nanostructures on carbon felt was developed on the base of pulse plating technique. Different in size, shape, and distribution, Ni-island nanostructures were deposited varying the potential, current, pulse duration, and cycle reiteration. The biocompatibility and nontoxicity of the newly created materials toward Candida melibiosica yeast cells was proven. The prepared Ni-nanomodified carbon felts were investigated as anodes in a two-chamber mediatorless yeast-biofuel cell. Maximum power density values of 720 and 390 mW/m(2) were achieved with the electrodes modified under galvanostatic and potentiostatic conditions, respectively, against 36 mW/m(2) for the nonmodified ones. The better biofuel cell performance obtained with the Ni-modified electrodes is assigned to an improved electron transfer.