Management of community-origin complicated intra-abdominal infections (cIAIs) requires surgical intervention and antimicrobial therapy. This multinational, randomised, double-blind clinical trial carried out in Asia compared the efficacy and safety of moxifloxacin monotherapy and ceftriaxone/metronidazole combination therapy in adults with confirmed or suspected cIAI. Patients received surgical intervention and either intravenous (i.v.) moxifloxacin 400 mg once daily or i.v. ceftriaxone 2 g once daily plus i.v. metronidazole 500 mg twice daily. A total of 364 patients were randomised [intent-to-treat (ITT), moxifloxacin N=180, comparator N=181; per-protocol (PP), moxifloxacin N=174, comparator N=171]. The most common cIAI diagnosis was complicated appendicitis. Moxifloxacin was non-inferior to ceftriaxone/metronidazole in terms of clinical response at test-of-cure in the PP population [clinical cure, 90.2% for moxifloxacin vs. 96.5% for ceftriaxone/metronidazole; 95% confidence interval (CI) of the difference -11.7 to -1.7] and in the ITT population (87.2% for moxifloxacin vs. 91.2% for ceftriaxone/metronidazole; 95% CI -10.7 to 1.9). Bacteriological cure rates in the microbiologically evaluable population support the clinical results (89.4% for moxifloxacin vs. 95.9% for ceftriaxone/metronidazole; 95% CI -13.3 to -0.6). The incidence of treatment-emergent adverse events was similar for both treatment groups (moxifloxacin 31.7% vs. comparator 24.3%). These results confirm previous findings that moxifloxacin plus adequate source control is an appropriate treatment of cIAI.