Aim: To assess the long-term safety of hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) 10% in European routine clinical practice.Materials & methods: This prospective, noninterventional, open-label, post-authorization safety study (EUPAS5812) sourced data on adverse events, immunogenicity, treatment regimens and product administration for 106 adult patients prescribed fSCIG 10% across 17 sites in six European countries from July 2014 to February 2020.Results: In total, 1171 treatment-emergent adverse events were reported in 94 patients (88.7%); 25.5% of these events were considered related to fSCIG 10%. Positive binding antibody titers developed in three patients; no neutralizing antibodies to recombinant human hyaluronidase were detected.Conclusion: This real-world study of fSCIG 10% is the longest to date and confirms its long-term safety and tolerability in adults with antibody deficiency diseases.