We report a direct method for the synthesis of Iron(III) oxyhydroxide (FeOOH) nanowalls using an electrochemical technique at room temperature. The length of the nanowalls can be varied depending on the number of repetitive potentiostatic pulse cycles during the electrochemical process. The samples were characterized by ex-situ techniques such as SEM, XPS, FTIR, and TEM. Field emission performances of these nanowalls are also reported for the first time. The measured turn-on electric field is about 4.8 V/microm, with emission current density of 0.12 mA/cm2 at 7.3 V/microm. This technique provides a simple alternative method for large area synthesis of FeOOH nanowalls.