Critical knee osteochondral defects in seven adult minipigs were treated with oligo(polyethylene glycol)fumarate (OPF) hydrogel combined with autologous or human adipose-derived stem cells (ASCs), and evaluated after 6 months. Four defects were made on the peripheral part of right trochleas (n = 28), and treated with OPF scaffold alone or pre-seeded with ASCs. A better quality cartilage tissue characterized by improved biomechanical properties and higher collagen type II expression was observed in the defects treated by autologous or human ASC-loaded OPF; similarly this approach induced the regeneration of more mature bone with upregulation of collagen type I expression. This study provides the evidence that both porcine and human adipose-derived stem cells associated to OPF hydrogel allow improving osteochondral defect regeneration in a minipig model.