Objectives: Determine flow criteria corresponding to LN4 histopathologic grade used for clinical staging of cutaneous T cell lymphoma (CTCL). Materials and Methods: Flow cytometry using primarily a panel of single antibodies was performed on 78 excised lymph nodes (LNs) from 72 patients with CTCL. Correlation with histopathologic grade was available for 64 specimens. Fifty-two LNs obtained at initial staging were used for prognostic correlations. Seventeen additional LNs were studied by fine needle aspiration (FNA). Results: Several flow criteria including CD4/CD8 ≥ 30, all CD7+ cells ≤ 20%, CD7/CD4 ≤ 0.4, CD71+ cells ≥ 20% and CD4/CD19 ≥ 8 had mean disease-specific survival rates comparable to that observed for patients with LN4 grade. However, less than 50% of LN4 nodes had these criteria. In a smaller subset of patients studied mostly by FNA, direct measurement of CD4+CD7- and/or CD4+CD26- cells provided quantitative data that also identified patients with survival rates similar to LN4 grade. The percentage of CD4+CD26- cells was typically higher than the percentage of CD4+CD7- cells. Conclusions: FNA is useful to assess enlarged peripheral LNs for involvement with CTCL. In conjunction with FNA, we propose that the maximum percentage of either CD4+CD7- and CD4+CD26- lymphocyte subsets ≥ 50% plus additional confirmatory evidence of involvement be used to define N3 rating and perforce sub-stage IVA2 . Additional studies are required to confirm these results and determine the role that FNA vis-à-vis excisional biopsy plays in the evaluation of patients with CTCL.