Background Papulopustular lesions (PPL) are commonly seen cutaneous lesions in Behçet's disease (BD). Some authorities do not recommend using cutaneous lesions for diagnostic criteria because these lesions are confused with acne vulgaris. Objective To understand if PPL have diagnostic value in BD. Methods Biopsy was performed on papulopustular lesions of Behçet's patients for histopathological examination to compare with the control group composed of patients with acne vulgaris. Forty two patients with BD and 21 control patients with acne vulgaris were enrolled in the study. Histopathological findings were classified as leukocytoclastic vasculitis, lymphocytic vasculitis, superficial and/or deep perivascular infiltration, and folliculitis and/or perifolliculitis. Results Of the specimens from 42 Behçet's disease patients, 7 (16.7%) revealed leukocytoclastic vasculitis and 3 (7.1%) had lymphocytic vasculitis, 15 (35.7%) had superficial perivascular and/or interstitial infiltration, 12 (28.6%) had superficial and deep perivascular and/or interstitial infiltration, 5 (11.9%) had folliculitis or perifolliculitis. Of the control group patients, 9 (42.9%) had folliculitis or perifolliculitis, 8 (38.1%) revealed superficial perivascular inflammation and 4 (19.0%) revealed mixed superficial and deep perivascular inflammation. Vasculitis was not encountered in any control group specimens. Vasculitis ratio was statistically higher in Behcet's disease patients (P = 0.016). Conclusions We evaluated more patients than previous related studies reported in the literature. Histopathological findings of vasculitis were encountered only in BD group. Non-vasculitis histopathological findings were also encountered in the control group patients. In conclusion, PPL can be used as a diagnostic criterion of BD subsequent to finding vasculitis in histopathological examination of the biopsy specimen of the PPL. © 2009 European Academy of Dermatology and Venereology.