The use of meta-analysis in medicine is widespread nowadays, particularly in the field of interventional cardiology. Meta-analysis is a statistical approach aiming to combine date from a large number of patients from randomized clinical studies and/or non-randomized registries so as to obtain a pooled estimate of the results and to answer specific research questions. It is important to take the correct methodological approach in order to reach unbiased conclusions. In this article, we provide an updated review of the methodological approaches needed to perform meta-analyses of non-randomized data, and we suggest a simplified check-list of items to be considered when attempting to deploy this kind of meta-analysis.