BACKGROUND: Symptomatic slow-acting drugs for osteoarthritis (SYSADOAs) are an important drug class in the treatment armamentarium for osteoarthritis (OA). OBJECTIVE: We aimed to re-assess the safety of various SYSADOAs in a comprehensive meta-analysis of randomized placebo-controlled trials, using, as much as possible, data from full safety reports. METHODS: We performed a systematic review and random-effects meta-analyses of randomized, double-blind, placebo-controlled trials that assessed adverse events (AEs) with various SYSADOAs in patients with OA. The databases MEDLINE, Cochrane Central Register of Controlled Trials (Ovid CENTRAL) and Scopus were searched. The primary outcomes were overall severe and serious AEs, as well as AEs involving the following Medical Dictionary for Regulatory Activities (MedDRA) system organ classes (SOCs): gastrointestinal, cardiac, vascular, nervous system, skin and subcutaneous tissue, musculoskeletal and connective tissue, renal and urinary system.