Following a facile two-step synthetic route (electrospinning and subsequent calcination), highly porous Mn2O3 nanofibers (empty set 105 nm) were fabricated. The as-prepared Mn2O3 nanofibers were applied to construct an amperometric sensor for hydrazine detection in neutral phosphate buffer. The developed hydrazine sensor showed a fast response time (within 5 s), a wide linear range up to 644 mu M, a high sensitivity of 474 mu A mM(-1) cm(-2), a good limit of detection of 0.3 mu M (S/N=3) as well as good reproducibility and selectivity. These results demonstrate that Mn2O3 nanofibers have great potential in the application of hydrazine detection.