In the spring of 1990 began the largest archaeological investigations thus far of the first urban centre in Sweden, called Birka. During the six years of the excavation, an archaeozoologist has been employed on site to organize and begin analysis of more than 5.5 tonnes of animal bones. This osteological material has proved to be unique, bath qualitatively and quantitatively, in the Swedish Viking Period. The analysis of the material (which has just begun) will give us both new and extended knowledge of Viking Period domestic animals and wild fauna in Central Sweden. This paper will present some of the new results, together with some future plans.