Hand osteoarthritis (OA) is a highly prevalent disorder, causing a considerable burden of disease. Simultaneous involvement of multiple hand joints and presence of different subsets (e.g., nodal, thumb base, and erosive OA) make it difficult to study. To advance our understanding, high-quality studies with optimal outcome measurement are essential. The Outcome Measures in Rheumatology (OMERACT) Hand OA Working Group (WG), assembled in 2010, endorsed a core domain set for clinical trials of symptom and structure modification and observational studies at OMERACT 2014, which was included in the Osteoarthritis Research Society International recommendations for design and conduct of clinical trials in hand OA.