This article analyzes the effects of extension services regarding the use of nutrients in Swedish agriculture on nutrient balances and farms’ finances. The key to our research design is that extension visits vary between agents (some agents give more consultation than others), which leads to random variation in “treatment.” We find that the service affects nutrient utilization, which possibly reduces leakages and eutrophication in the Baltic Sea. A large and positive impact on farms value added implies that the net benefit from the extension services is positive. The improvements are mainly due to better land management practices so that more efficient use of fertilizers increases crop production and thereby decreases the nitrogen balance.