Natural fibers offer good prospective as reinforcements in polymer composites due to their superior properties, they are preferred over synthetic fibers in various applications such as construction, automotive and aerospace. This experimental study emphasizes the effect of nonwoven structure on the mechanical, thermal and biodegradability properties of feathers nonwoven reinforced polyester composite. Vacuum molding method was adopted for manufacturing of the biocomposites with two contents of polyester resin (30% and 50%) and different composition of nonwovens. As a result, the morphological analysis revealed excellent compatibility and regular distribution of fiber in the polyester matrix. The thermal conductivity of manufactured composites varies considerably from 0.0378 W/(m•K) to 0.0778 W/(m•K) at 10°C. The origin of the variation of this property is due to differences in composition of nonwovens, densities and the percentage of the resin. After soaking for 240 h, the biodegradability test show that the kinetics of degradation of the composites decreased with the addition of nonwovens. The biodegradability rate was found between 62 to 92% depending on the sample nature. The mechanical results showed that the nonwoven structure clearly affected the performance of the composites. The results obtained from this study can be useful to develop new low cost, sustainable, light product and environmentally friendly materials.