Two of the most important microscopically derived morphologic prognostic factors for breast carcinoma patients are histologic type of tumor and nuclear grade. The recent literature stresses the importance of including these parameters in the surgical pathology report, yet there is little information in the cytology literature regarding the reporting of the nuclear grade of breast carcinomas from fine-needle aspirate biopsies (FNAB). In this retrospective study, we examined 104 ductal carcinomas of the breast in order to determine whether the FNAB derived nuclear grade and morphologic aspects of histological grading such as tubule formation and mitoses could accurately correlate with the same parameters on the tissue specimens. There was a correlation of 87% between the nuclear grade assigned by FNAB and the nuclear grade assigned to the tissue sample. Both the Diff-Quik and the Papanicolaou staining methods were assessed in this study and both gave comparable nuclear grade results. Tubule formation was difficult to assess on the cytologic samples and mitoses showed no correlation between cytologic and tissue specimens. The FNAB sample was not representative of the tissue nuclear grade in only 4.8% of the cases. Nuclear grade is especially important in patients treated with chemotherapy prior to definitive therapy for breast carcinoma. We conclude that the nuclear grading of breast carcinomas is performed with ease, correlates well with tissue nuclear grade, and, as a fundamental cytologic parameter, should be included in the fine-needle aspirate biopsy report whenever possible.