Objective: To explore the clinical efficacy of modified Dachaihu decoction with Sijin decoction combined with conventional conservative treatment for cholecystolithiasis with acute cholecystitis. Methods: 109 patients with cholecystolithiasis complicated with acute cholecystitis were classified into control group (n=54, conventional treatment) and combined group (n=55, conventional treatment plus modified Dachaihu decoction with Sijin decoction) based on treatment methods. The efficacy, TCM symptoms scores, pain degree [visual analog scale (VAS) score] and inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6) and interleukin-8 (IL-8) levels] and incidence of adverse reactions were compared between the two group. Results: Compared with the control group, the clinical efficacy in the combined group was improved, and the TCM syndromes scores were decreased after treatment (P<0.05). The VAS scores in both groups after 3 and 7 days of treatment were reduced, and the VAS scores were lower in the combined group compared to the control group (P<0.05). After treatment, the levels of CRP, IL-6 and IL-8 were decreased in the two groups, and the combined group had lower CRP, IL-6 and IL-8 levels than the control group (P<0.05). There was no statistically significant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion: Modified Dachaihu decoction with Sijin decoction combined with conventional conservative treatment has significant efficacy on cholecystolithiasis with acute cholecystitis, and it can effectively improve the clinical symptoms of patients, and relieve the pain and inflammatory response, with high safety.