This paper presents a two-dimensional analysis for the efficiency of an elliptic tin under the dry, partially wet and fully wet conditions of a range of value for axis ratios, Biot numbers, and air humidities. It is shown that the fin efficiencies increase as the axis ratio Ar is increased. For a given axis ratio Ar, the fin efficiency decreases as the fin height l* or Biot number is increased. The conventional I-D sector method overestimates the fin efficiency resulting in increasing error as the axis ratio Ar is increased. In addition, using experimentally determined heat transfer coefficients, it is found that both the fully dry and wet elliptic fin efficiencies are up to 4-8% greater than the corresponding circular fin efficiencies having the same perimeter.