Human immunoglobulin is an established replacement therapy for patients with primary immunodeficiency disorders (PIDs). Recombinant human hyaluronidase (rHuPH20) is a spreading factor that temporarily digests hyaluronan in the skin interstitium enabling large volumes of fluid or drug solutions to be infused and absorbed subcutaneously. HyQvia® (IGHy) is a new combination product whereby rHuPH20 is injected subcutaneously, followed by human immunoglobulin 10 % infused through the same needle. Thus, IGHy can be administered at a reduced frequency compared with non-facilitated subcutaneous injection of human immunoglobulin, and with a lower frequency of infusion reactions than with intravenous administration. Home-based administration of IGHy is also feasible for adequately trained patients. IGHy was compared with intravenous human immunoglobulin 10 % in a non-randomized, open-label, phase 3 study in patients aged ≥2 years with PIDs who were receiving human immunoglobulin replacement therapy (n = 87). In this study, trough IgG concentrations, acute serious bacterial infection rates (primary endpoint) and occurrences of adverse events during the IGHy treatment period were generally similar to those observed during an intravenous treatment period. IGHy was associated with a numerically lower rate of systemic adverse events and a numerically higher rate of localized adverse events than those observed with intravenous treatment. Compared with intravenous administration, IGHy was administered at a significantly higher maximum flow rate and at a similar frequency. Most patients preferred IGHy over intravenous administration. IGHy offers a new method for subcutaneous delivery of human immunoglobulin replacement therapy in patients with PIDs.