Promising biodegradable and renewable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nano composites based on tungsten disulphide inorganic nanotubes (INT-WS2) were efficiently prepared by a simple solution blending method. The structure, morphology, thermal stability and crystallization behavior of the nanocomposites were investigated by ultra-high field-emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS) and polarized optical microscopy (POM) techniques. As previously observed in poly(3-hydroxybutyrate) (PHB) hybrid systems, the dispersion, morphology and thermal properties of PHBV/INT-WS2 nanocomposites could be tuned by the introduction of small amounts of INT-WS2. The results revealed that a good dispersion of INT-WS2 in the PHBV matrix influenced the morphology and non-isothermal crystallization behavior of PHBV that depends on both the INT-WS2 concentration and the cooling rate. A significant enhancement in thermal stability of PHBV and a highly efficient nucleating effect of the INT-WS2 comparable to specific nucleating agents or other nano-sized fillers was observed. These observations are of importance for extending the practical applications of these biopolymer nanocomposites towards eco-friendly (e.g. sustainable packaging) and biomedical (e.g. bone tissue engineering) applications. (C) 2015 Elsevier B.V. All rights reserved.