OBJECTIVES: The use of bacterial lysates as an immuno-modulator to boost immunological response in patients with Recurrent Respiratory Tract Infections and its effects on the attack frequency of respiratory infection have been widely debated. We aimed to conduct our meta-analysis on the effect of bacterial lysates plus routine care versus routine care only on the attack frequency of respiratory infection in patients with Recurrent Respiratory Tract Infections. METHODS: We performed a systematic review of articles published from Jan 1, 2000 to Nov 10, 2013 by searching PubMed, Embase, Cochrane Central Register of Controlled Trials, and Wanfang and China National Knowledge Infrastructure. We included all randomised trials that compared outcomes between patients with Recurrent Respiratory Tract Infections receiving bacterial lysates plus routine care with those receiving routione care only. Eligible studies, determined by consensus with predefined criteria, were reviewed and data were extracted onto a standard form. We combined data to assess the primary outcome of attack frequency of respiratory infection using the DerSimonian and Laird random effects model. RESULTS: Our search identified 128 reports, of which twelve studies met our inclusion criteria and were included in our meta-analysis. Analysis of the 12 randomised trials (959 patients) that reported an outcome on the attack frequency of respiratory infection showed that patients assigned to bacterial lysates plus routine care had a 2.942 reduction in respiratory tract infections compared to those assigned to routine care only (Weighted Mean Difference -2.942, 95% CI -3.600, -2.284). CONCLUSIONS: Bacterial lysates are associated with a decreased risk of respiratory tract infections in patients with Recurrent Respiratory Tract Infections. Further studies are needed to identify the causes of respiratory tract infections and to assess whether the attack frequency of respiratory infection differs with varying treatments of bacterial lysates.