Few and contrasting data are available in the literature concerning the levels of various cytokines in blister fluid (BF) and in the serum of patients affected with bullous pemphigoid (BP). Using commercially available ELISA kits, this study reports the levels of 11 cytokines detected both in BF and sera of 15 BP patients and compares them with those of 15 control subjects' sera. Generally, no significant differences were observed in BP and control sera. In contrast, interleukin (IL) 1β, IL-2, IL-4, IL-5, IL-6, IL-8, tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) showed increased BF levels as compared with BP sera. Two cytokines, IL-11 and IL-12 did not show significant differences between BP BF and sera, while an opposite behaviour was observed for transforming growth factor β1 (TGF-β1), whose serum levels were higher than the concentrations in BF. Using the number of lesions of the patients as a possible disease intensity marker, significant correlations were found with the BF levels of IL-1β, IL-8, TNF-α and, most closely, IL-5. These data may have pathogenetic relevance and suggest the possibility that these biological modulators may be used as a quantitative marker of disease intensity.