The use of biofertilizers has increased in Brazil mainly due to the search for inputs that are less harmful to the environment and to enable the development of an agriculture less dependent on industrial products. The aim of this study was to evaluate the performance of melon grown with the use of biofertilizers in area Mossoró / Açu. For this purpose, two experiments were conducted in the teaching garden of the Department of Plant Sciences UFERSA in Mossoró, RN, from May to December 2010. In the first experiment, the chemical composition of biofertilizers (animal manure and chicken) at different stages of decomposition, the experiment was randomized in a factorial 2 x 7 with three replications. Treatments consisted of a combination of two sources of manure (cattle and chicken) and seven days of decomposition (0, 5, 10, 15, 20, 25 and 30 days). In the second experiment, performance of melon with application of bio-fertilizers, fertigation, the experimental design was randomized complete blocks with four replications in a 2 x 5. The treatments were a combination of two sources of manure used in the preparation of biofertilizer (cattle manure and chicken) and five doses (0, 25, 50, 75 and 100%) applied by fertigation. The highest concentrations of nutrients, dry matter and electrical conductivity were obtained in biofertilizer produced with chicken manure. The order of nutrients was observed in biofertilizers K, N, P, Ca and Mg. The nutrients showed higher within 15 to 20 days of decomposition with the exception of nitrogen that was more concentrated on the preparation of biofertilizer. The highest yield of fruits was observed when we used 25% of potassium in the form of biofertilizer. The quality characteristics like acidity and bark thickness showed an effect to the use of biofertilizer doses.