The aim of the present work was to calculate nutrient balances for organic pig farms. 75 project farms with 3 different husbandry systems were located in eight European countries. Balance sheets on individual farm level were based on the total farm gate balance. The results were compared for the husbandry systems "indoor", "outdoor" and "partly outdoor" and the impact of the individual input and output factors was tested. Based on the results, options were discussed for a reduction of nutrient surplus. Differences were found regarding Nitrogen between the individual farms, but not between the husbandry systems. However, there were significant differences in the results for phosphorus balance, both between individual farms and husbandry systems. Nutrient surplus was mainly caused by the factor “import via purchased feed and straw”, which represents the highest risk factor for an imbalance in N and P. High stocking densities and small farm areas are leading to high nutrient inputs because the feed demand cannot be covered by own production. The result is a high feed import. In organic pig farming it is important to manage nutrient cycles properly. Thereby environmental pollution can be reduced. To achieve balanced nutrient flows as far as possible, it is advantageous to adapt the stocking densities to the agricultural conditions of the farm. On the one hand, permanently positive balances lead to the pollution of the environment, while economic losses occur as a consequence of large imports of feed and fertilizer. Over time, negative nutrient balances on the other hand lead to the depletion of nutrients in the soil, which in turn can lead to economic losses in the operation. Soil management and animal husbandry must be consistent in order to minimize the environmental impact.