Agro-waste and fibrous solid residues obtained from the processing of agricultural products have been exploited to obtain new polymeric composites, where the residues act as filler for the polymeric matrix. The agro-waste residues were i) white and red (Garganega and Merlot) grape pomace and shoots (in collaboration with the University of Montpellier), ii) residues derived after extraction of active molecules, such as polyphenols, from grape pomace, iii) residues derived from the potato starch extraction. Residues, after a characterization by thermogravimetric analysis in order to evaluate their thermal stability at the polymer processing temperatures (180-200°C), have been dried in an oven at 60°C for 24 h and milled. Then, the composite preparation has been carried out by melt mixing in a Brabender mixer the residues with the renewable and biodegradable PHBV polymer, following a green approach (solvent-less process). The solid residues, derived from winery waste (pomace and shoots) and from solvent and pressurised-liquid extractions, were mixed in a content variable between 5 and 20% by weight. The composites showed thermal and mechanical properties that were only slightly modified with respect to those of the matrix despite the presence of a significant percentage of a second component, that acted as a filler. The added residue was compatible with the polymeric matrix and does not present main problems in processing: therefore, the composites could find application in horticulture sector or the packaging area. Analogously to winery residues, the potato residue was included as a filler into PHBV matrix up to 40 wt%. The thermal properties were not affected by the filler presence. In particular, the potato residue does not interfere with the crystallization and melting behaviour of PHBV. The mechanical properties decreased but not proportionally to the very high amount of filler: even if the polymeric matrix amount was almost halved, the biocomposites still presented properties suitable for practical applications. The use of both pomace and potato residues in biocomposites could, therefore, bring both to the reduction of the cost of the final material, as a lower amount of costly PHBV is used, and to the improvement of a few material properties, as well as to the full valorisation of agro-wastes and the production of a new materials that are potentially biodegradable.