The present invention relates to a device and method for measuring hemoglobin in a fluid sample. The device comprises a disposable electrochemical cell, such as a thin layer electrochemical cell, containing a reagent capable of being reduced by hemoglobin. A suitable fluid sample that may be analyzed according the present invention is whole blood. If the hemoglobin to be analyzed is present in red blood cells, a lysing agent may be added to the sample to release the hemoglobin prior to analysis.