Introduction. Systematic reviews are fundamental sources of knowledge on the state-of-the-art interventions for various clinical problems. One of the essential components in carrying out a systematic review is that of developing a comprehensive literature search. Materials and methods. Three Cochrane systematic reviews published in 2012 were retrieved using the MeSH descriptor breast neoplasms/surgery, and analyzed with respect to the information sources used and the search strategies adopted. In March 2014, an update of one of the reviews retrieved was also considered in the study. Results. The number of databases queried for each review ranged between three and seven. All the reviews reported the search strategies adopted, however some only partially. All the reviews explicitly claimed that the searches applied no language restriction although sources such as the free database Lilacs (in Spanish and Portuguese) was not consulted. Conclusion. To improve the quality it is necessary to apply standards in carrying out systematic reviews (as laid down in the MECIR project). To meet these standards concerning literature searching, professional information retrieval specialist staff should be involved. The peer review committee in charge of evaluating the publication of a systematic review should also include specialists in information retrieval for assessing the quality of the literature search.