For transdermal delivery of porcine placenta extract (PPE), various emulsion formulations were prepared and evaluated. Polysorbate surfactants were used as emulsifiers and various C-18 unsaturated fatty acids as enhancers. The skin permeation of PPE was tested using a cellulose nitrate membrane-loaded Franz cell apparatus. Among emulsifiers, Tween 20 provided higher penetration effect than did Tween 80. Meanwhile, of various fatty acids, linolenic acid (18:3) revealed the highest skin permeation of PPE than the other C-18 unsaturated fatty acids. Stability of PPE emulsions was determined by cycles of freezing and thawing processes. The stability of emulsions depended on the percentage of Tween 20. Minimum 20% of Tween 20 was required to stabilize emulsions at room temperature for several days. Taken together, our results suggest that Tween 20 and linolenic acids might be key components to formulate PPE emulsion to provide the desirable skin permeability and stability.