The effect of filler loading and in situ salicylic acid treatment on the mechanical properties and morphology of poly(hydroxybutyrate-co-valerate)/corn husk fiber (PHBV/CHF) biocomposites was studied. Both untreated and salicylic acid treated PHBV/CHF biocomposites were prepared by using heated two roll mill followed by compression moulding. It was found that the addition of CHF to PHBV biocomposites increased the tensile strength and Young’s modulus while the elongation at break decreased. Salicylic acid treated PHBV/CHF biocomposite display superior tensile strength and Young’s modulus than untreated PHBV/CHF biocomposite due to the enhanced filler–matrix interaction. The better interfacial adhesion between CHF and PHBV matrix was confirmed through scanning electron microscope (SEM) analysis.