Fine needle aspiration (FNA) cytology of the breast is a useful method for diagnosing breast lesions. Yet making the definite diagnosis with performing FNA is limited by some problems, such as the low cellularity, the poor preservation and the obscuring background. Recent studies have found that liquid-based cytology solves such problems, but it is an expensive method and it is limited by the loss of the background information. The purpose of this study is to compare the Liqui-PREP(TM), a new manual liquid-based method of cytology, and the conventional smears for analyzing breast FNA cytology materials. A total of 31 randomized FNA specimens of breast were studied. In each case, both the conventional smears and the Liqui-PREP(TM) method were performed, and the smears were evaluated for cellularity, cellular preservation, the background, the cytologic features and the architectural arrangement. The cellularity and architectural arrangement were equal for both preparations. The Liqui-PREP(TM) specimens showed better cellular preservation, loss of the obscuring background, no overlapping of cells and a smaller area to screen compared with the conventional smears. Moreover, it has the potential advantages of being able to use the remaining specimens for immunohistochemical study and ploidy analysis, and it can reduce the costs for preparation compared with the other liquid-based methods of cytology. But some background information is lost in the Liqui-PREP(TM) specimens, the same as the other liquid-based methods of cytology. In conclusion, the Liqui-PREP(TM) and conventional smears showed good correlation, but they have their respective advantages and disadvantages. These results suggest that Liqui-PREP(TM) can contribute to making the accurate diagnosis with performing breast FNA cytology when it is used along with other methods.