Background: Worldwide, pneumonia is the leading cause of death among children under five years of age and accounts for approximately two million deaths annually. The World Health Organization (WHO) has developed case management guidelines based on simple clinical signs to help clinicians decide on the appropriate pneumonia treatment. Children and infants who exhibit fast breathing (50 breaths per minute or more in infants two months to 12 months of age and 40 or more in children 12 months to five years of age) and cough are presumed to have non-severe pneumonia and the WHO recommends antibiotics. Implementation of these guidelines to identify and manage pneumonia at the community level has been shown to reduce acute respiratory infection (ARI)-related mortality by 36%, although apprehension exists regarding these results due to the questionable quality of evidence. As WHO guidelines do not make a distinction between viral and bacterial pneumonia, these children continue to receive antibiotics because of the concern that it may not be safe to do otherwise. Therefore, it is essential to explore the role of antibiotics in children with WHO-defined non-severe pneumonia and wheeze and to develop effective guidelines for initial antibiotic treatment. Objectives: To evaluate the efficacy of antibiotic therapy versus no antibiotic therapy for children aged two to 59 months with WHO-defined non-severe pneumonia and wheeze. Search methods: We searched CENTRAL (2014, Issue 1), MEDLINE (1946 to March week 3, 2014), EMBASE (January 2010 to March 2014), CINAHL (1981 to March 2014), LILACS (1982 to March 2014), Networked Digital Library of Theses and Dissertations (23 July 2013) and Web of Science (1985 to March 2014). Selection criteria: Randomised controlled trials (RCTs) evaluating the efficacy of antibiotic therapy versus no antibiotic therapy for children aged two to 59 months with non-severe pneumonia and wheeze. We considered studies that defined non-severe pneumonia as cough or difficulty in breathing with a respiratory rate above the WHO-defined age-specific values (respiratory rate of 50 breaths per minute or more for children aged two to 12 months, or a respiratory rate of 40 breaths per minute or more for children aged 12 to 59 months) and wheeze for inclusion. We have excluded non-RCTs (quasi-RCTs). Data collection and analysis: Two review authors independently assessed the search results and extracted data. Main results: We did not identify any study that completely fulfilled our inclusion criteria. Authors' conclusions: There is a clear need for RCTs to address this question in representative populations. We do not currently have evidence to support or challenge the continued use of antibiotics for the treatment of non-severe pneumonia, as suggested by WHO guidelines.