Aim of the study was to characterise the influence of heat treatment on the degradation behaviour and stability of degradable magnesium based implants. For this purpose two groups (untreated/ heat treated) of LAE442 pins were separately analysed in an in vitro and in vivo study. The corrosion behaviour was evaluated during 8 weeks degradation in SBF (in vitro) and 48 weeks degradation intramedullary in the rabbit tibia (in vivo). The analyses were made by using μ-computed tomography and three-point-bending tests. Heat treatment led to altered mechanical and corrosion properties of LAE442.While the initial stability declined significantly a reduction of the degradation rate over either in vitro and in vivo evaluation period is determined. If these alterations are still reasonable for osteosynthesis implants remains to be investigated in further projects.