Papillary metaplastic changes especially occur in both non-neoplastic and neoplastic endometrium. We tried to investigate to assess the relationship between endometrial cytologic diagnosis and papillary metaplasia. The material consists of 160 cases of cytologic smears obtained by direct sampling of the endometrial cavity comprising 54 cases of normal proliferative endometrium (NPE), 36 cases of glandular and stromal breakdown (EGBD), and 70 cases of endometrial hyperplasia without atypia (EH). As for the correlation between the appearance of papillary metaplasia and cytological diagnosis, a statistical significance test was performed. The material consists of 40 cases of cytologic smears examined by direct sampling of the endometrial cavity comprising 10 cases of EGBD with papillary metaplasia, 10 cases of G1 without papillary metaplasia, 10 cases of NPE without papillary metaplasia, and 10 cases of EH without papillary metaplasia. Using the comparison between appearance of papillary metaplasia and cytological diagnosis, a significant difference was only seen in the rate of correct diagnoses in EGBD cases. The nuclear area of papillary metaplastic cells in EGBD was 888.8, G1 was 928.7, NPE was 682.0, and EH was 722.2. Significant difference was observed between ECC cells in EGBD to NPE, between papillary metaplastic cells in EGBD to EH, between G1 to NPE, or between G1 to EH. This study provides new and important information on the correlation between endometrial cytological diagnosis and papillary metaplastic changes.