Reduction of the inappropriate use of antibiotics in clinical practice is one of the main goals of the Società Italiana di Medicina Interna (SIMI) choosing wisely campaign. We conducted a systematic review of secondary studies (systematic reviews and guidelines) to verify what evidence is available on the duration of antibiotic treatment in Pneumonia. A literature systematic search was performed to identify all systematic reviews and the three most cited and recent guidelines that address the duration of antibiotic therapy in pneumonia. Moreover, a meta-analysis of non-duplicate data from randomized controlled trials (RCTs) considered in the enrolled systematic reviews was performed together with a trial sequential analysis to identify the need for further studies. Two systematic reviews on antibiotic duration in community-acquired pneumonia (CAP) for a total of 17 RCTs (2764 patients) were enrolled in our study. Meta-analysis of non-duplicate RCTs show a non-significant difference in rate of treatment failure between short (≤ 7 days) and long (> 7 days) antibiotic treatment course: RR 1.05 (95% CI, 0.82-1.36). The trial sequential analysis suggests that further data would not affect current evidence or become clinically relevant. Selected guidelines suggest consideration of a short course, with a low grade of evidence and without citing the already published systematic reviews. Antibiotic treatment of CAP for ≤ 7 days is not associated with a higher rate of treatment failure than longer courses and should thus be taken in consideration. Guidelines should upgrade the evidence on this topic.