Introduction: The use of retro-orbital blood sampling is prohibited in Denmark. For this reason, alternative methods are used for obtaining larger blood samples of a good quality. The facial vein is generally recommended for this. However, we have experienced discomfort for mice subjected to facial vein blood sampling. Therefore, we investigated if this technique was associated with pathological changes of the jaw region. Methods: 43 NMRI mice were subjected to facial vein blood sampling by using the lancet method during 12 months, starting at the age of 8 weeks. The mice were restrained manually by the scruff and a lancet was placed 2-3 mm caudally to the freckle on the lower jaw, and the skin was punctured. After sampling, brief compression by a cotton swab was applied, if bleeding did not stop. Two days after the last blood sampling, the mice were euthanized by an overdose of pentobarbital, and the tissue of the jaw was evaluated. Results: In the 23 mice, from which blood samples had been taken 2 days previously, 5 mice had no signs of gross pathological changes, whereas 12 mice had signs of minimal local subcutaneous bleeding and 6 mice had moderate local subcutaneous bleeding. No additional gross pathological changes were observed. In the 23 mice, from which blood samples had been taken 4 weeks earlier, no hemorrhage or signs of scar tissue formation could be observed. Histological slides are currently being processed (HE staining) and will be evaluated and discussed.