The paper presents preliminary results of the implantation of calcium sulfate type Hartform HF1 developed at the Institute of Glass and Ceramics in Warsaw. The study was conducted on 10 New Zealand White rabbits, in which after tibial osteotomy the biomaterial was implanted directly into the fracture site. The animals were divided into two groups based on the method of fracture stabilisation: intramedullary pinning using Kirschner wires in one group and acrylic external fixator in the other. After 12 weeks, bone union was observed in all animals as estimated by clinical and radiological findings. Histological tests revealed resorption of the biomaterial into the bone fracture area. It was concluded that type Hartform 1 calcium sulfate can be used as a biomaterial in veterinary orthopedics. Due to the lack of observable side effects during implantation and resorption, the material can be considered as a valuable ingredient in composite biomaterials containing calcium sulfate.