The motive of palmprint image enhancement is to highlight the fine details of palm lines. In this paper, a fuzzy unsharp masking algorithm is presented to enhance the contrast of a palmprint image. This method introduces the fuzzy set theory into the unsharp masking scheme. Unsharp masking (UM) approaches are simple and effective for contrast enhancement of high-frequency components. Most of UM algorithms can effectively improve the contrast of principal lines, but insensitive to wrinkles. In order to further enhance the contrast of wrinkles, a half open membership function is used to transform the output of the filters into fuzzy domain. The palmprint image is enhanced in fuzzy field. The proposed method is compared with other techniques in the paper and the experimental result demonstrates that the proposed approach can enhance the fine details of palmprint image effectively.