Aim: Hand joints are the main target in rheumatoid arthritis (RA) and hand involvement in terms of thickening of the skin and contractures are also well known in systemic sclerosis (SSc). Assessment of hand function in SSc is generally an overlooked entity with respect to RA. Therefore the aim of this study was to compare hand functions and potential influence of functional loss on patients' overall physical functions, health-related quality of life (HRQoL) and psychological status in RA and SSc. Methods: Age- and gender-matched adult patients with SSc and RA were consecutively recruited. Patients' hand functions were evaluated by using the Duruöz Hand Index (DHI), and hand span and hand grip strength were measured. Patients were evaluated for disease-specific and generic outcome measures including disease activity parameters and HRQoL measures. Results: Fifty patients (44 female, six male) with SSc and 51 (45 female, six male) with RA were included. Despite similar functioning and HRQoL, patients with RA had higher visual analog scale-pain and body mass index. In both groups DHI revealed similar functional loss and correlated with various measurements related to HRQoL. In SSc, hand span, grip strength and modified Rodnan skin score had major influences on hand functions. Conclusion: Assessment of hand function is an important component in the clinical evaluation of patients with RA and SSc. Loss of hand functions is an important feature contributing negatively to the overall physical status and HRQoL in patients with SSc and may be more frequent and important than expected.