Background: The recruitment to the skin of drug-responsive T cellS is responsible for the inflammatory profiles of non immediate drug hypersensitivity reactions (niDHRs). Maculopapular exanthema (MPE) and Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) have quite distinct T cell infiltrating patterns. Objective: To investigate serum levels of CXCL9, CXCL10 and IFN-gamma in patients with niDHRs, including MPE and SJS/TEN, to evaluate correlations between the cytokines, and to determine whether the inflammatory factors correlate with clinical severity in patients with SJS/TEN. Method: Twenty-four patients with SJS/TEN, 24 patients with MPE, and 24 healthy donors with good tolerance:to the drugs involved in the drug reactions were recruited into the study. The modified severity-of-illness score for TEN (SCORTEN) and detachment of body surface area (dBSA) were Used to assess the clinical severity of SJS/TEN. Serum levels of CXCL9, CXCL10 and IFN-gamma were determined by ELISA.: Results: The niDHRs group, SJS/TEN and MPE subgroups all exhibited significantly higher levels of CXCL9; CXCL10 and IFN-gamma compared with the control group (P < 0.001): Serum IFN-gamma levels were positively correlated with CXCL9 levels and CXCL10 levels in patients with niDHRs (r(s) = 0.576, r(s) = 0.449, P < 0.05). None of the levels of CXCL9, XXCL10 and IEN-gamma had any correlation with modified SCOTEN index or dBSA in SJS/TEN group. Conclusions: The results suggest Th1 cytokine IFN-gamma and chemokines CXCL9 and CXCL10 may play roles in the pathogenesis of niDHRs.