Laser beam welding was used successfully to join the Oxide Dispersion Strengthened Super alloy PM1000 for a range of welding conditions. A microscopical study revealed a disturbed structure of dendrites and micro sized particles, which were formed during the molten state of the weld process. Although the particles are a result of melting and clustering of the yttrium oxide particles, tensile tests at high temperatures showed only a minor decrease of strength. It is found that the morphology of the weld, which is closely related to the heat input, has a strong influence on its failure behavior at elevated temperatures.