Objective To systematically evaluate the effectiveness of N-acetylcysteine (NAC) combined with low-dose glucocorticoid for patients with idiopathic pulmonary fibrosis (IPF). Methods Such databases as The Cochrane Library (Issue 12, 2012), EMbase (January 1974 to July 2012), PubMed (January 1966 to July 2012), CHEST (January 1995 to July 2012), CNKI (January 1994 to July 2012), CBM (January 1978 to July 2012), VIP (January 1989 to July 2012) and WanFang Data (January 1995 to July 2012) were searched to collect the randomized controlled trials (RCTs) about NAC combined with low-dose glucocorticoid versus glucocorticoid alone for IPF patients. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the quality, and then the meta-analysis was performed using RevMan 5.1 software. Results A total of seven RCTs including 264 IPF patients were included. The results of meta-analysis demonstrated that, compared with the glucocorticoid used alone, a) NAC combined with low-dose glucocorticoid could significantly improve PaO2 (SMD=0.82 mmHg, 95%CI 0.30 to 1.35, P=0.002) and DLco (SMD=0.59 mmHg, 95%CI 0.16 to 1.03, P=0.008) with a significant difference. b) NAC combined with low-dose glucocorticoid could significantly improve all clinical symptoms (RR=1.56, 95%CI 1.26 to 1.92, Plt;0.000 1). Conclusion NAC combined with low-dose glucocorticoid for IPF patients can significantly improve PaO2, DLco, and the clinical symptoms such as cough, difficulty breathing after activities, cyanosis, and Velcro rales. Due to the quantity and quality limitation of included studies, this conclusion still needs to be further proved by more high quality and double blind RCTs.