The use of recycled polymers and agricultural waste could be an important tool to reduce the environment impact of plastic manufacts and to valorize the agricultural waste. In this work recycled PP and hazelnuts shells were used in order to produce green composites to be applied for the production of fittings for irrigation systems. In order to improve the poor adhesion between matrix and filler an adhesion promoter was also used. The adhesion improves in particular for the composites with the recycled polymer probably because of the presence of polar groups in the recycled sample. The rheological properties clearly indicate that the composites show a processability similar to that of the pure polypropylene and this feature has been corroborated by industrial preliminary injection molded tests where the fitting was easily produced. The deformability of the composites is reduced with respect to the pure matrix although slightly improved by the presence of the adhesion promoter. The composite with RPP as matrix and 5% of hazelnut shells with and without adhesion promoter were also used to produce a fitting by injection molding and all the fittings were resistant to the water pressure of 3.50 bar according to the internal test used by the company