In the paper the balance of nitrogen in seventy eight selected farms of three communities of Leszno region is presented. Results concern: livestock density, production of nitrogen in animal organic fertilizers, balance of nitrogen in farms as well as for cultwated plants. Production of nitrogen in animal organic fertilizers and its balance were compared to regulation in force in Poland. It has been stated that in examined farms the livestock density was high (in 67,9 % of farms over 1 large livestock unit) and in four farms the production of nitrogen in animal organic fertilizers and it's applied doses were larger than allowed quantity of170 kg per 1 ha of agriculturally utilized area. In 33 farms (42,3 % of total farms) the positive balance difference of nitrogen (brought in organic and mineral fertilizers minus uptake in yields of plants) was larger than allowed 30 kg/ha ofUAA. Among cultivated plants in examined farms the highest positive balance value of nitrogen was stated in case of fodder beet, potato, winter and spring barley cultivation.