The activation of the Toll-like receptor 4 (TLR4)/nuclear factor-kappaB (NF-kappaB) pathway has been implicated as a key mediator in the pathogenesis of ulcerative colitis (UC); therefore, it has become an attractive target for the treatment of UC. Qing Hua Chang Yin (QHCY) is a traditional Chinese formula, which has been used for many years to clinically treat conditions associated with inflammatory bowel diseases, such as UC. However, the precise mechanisms behind its anti-inflammatory effects remain largely unknown. In this study, using the dextran sulfate sodium (DSS)-induced colitis mouse model, we evaluated the therapeutic effects of QHCY against UC and elucidated the possible underlying molecular mechanisms. We found that the administration of QHCY profoundly ameliorated DSS-induced clinical manifestations, colon shortening and histological damage in the mice with colitis. In addition, treatment with QHCY significantly decreased the DSS-induced secretion of serum amylase. Moreover, QHCY significantly inhibited the DSS-induced expression of TLR4 and myeloid differentiation primary response gene 88 (MyD88), the phosphorylation of IkappaB and the nuclear translocation of NF-kappaB. Taken together, our findings suggest that the suppression of the TLR4/NF-kappaB signaling pathway may be one of the mechanisms involved in the therapeutic effects of QHCY against UC.