The aim of this study was to improve the electrospinning parameters and evaluate the effects of Multi-Walled Carbon Nano-Tubes (MWNTs) on the structural and mechanical properties of Poly-3-hydroxybutyrate (P3HB) electrospun scaffolds. To this end, to achieve optimal properties of the electrospinning machine, P3HB polymer solutions were prepared at different concentrations and spinned. After optimization, MWNTs at different weight percentages (0.5%, 0.75%, 1% and 1.25%) were added to the polymer solutions and electrospinned. The effects of different concentrations of MWNTs on the structure of fibers and properties of the scaffolds were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Evaluation of the scaffold morphology showed the presence of MWNTs into fibers, that Adding different amounts of nanotubes increased the average diameter of the fibers,with the mean increase reaching 700 nm from 240 nm. In addition, evaluation of porosity with the use of SEM photomicrographs and the MATLAB software program showed an increase in porosity from 81% to 84% in the presence of MWNTs. The analysis of mechanical properties of the PLGA/MWNTs composites revealed 158% improvement over pure PHB scaffold, So that the tensile strength in presence of only 0.5% MWNTs increased from 2 to 5.15 MPa. According to mechanical and structural properties obtained, the best amount of MWNTs was 0.5 wt%. Therefore, it is possible to significantly improve the structural and mechanical properties of pure P3HB scaffolds by incorporating some MWNTs to their structure so that they can become favorable for tissue engineering applications.