Nitrogen-doped carbon nanotube (N-CNTs) were synthesized via a chemical vapor deposition (CVD) method using three iron (Fe) catalyst to aluminum substrate (C/S) ratios, i.e., 10, 20, and 40 wt.% Fe, namely (N-CNTs)10, (N-CNTs)20, and (N-CNTs)40, respectively. Employing TEM, XPS, Raman spectroscopy, and TGA techniques, it was revealed that C/S ratio has a significant impact on the physical (e.g., diameter, length, and crystallinity) and chemical (e.g., carbon purity, nitrogen content, and nitrogen-bonding type) properties. For instance, by increasing Fe catalyst from 10 wt% to 40 wt%, carbon purity and length of nanotubes increased from 60 to 90 wt% and from 1.2 to 2.6 µm, respectively. Interestingly, with regard to nanotubes’ morphology, at high C/S ratio, the N-CNTs are open-channel while at low catalyst concentration the nanotubes feature a bamboo-like structure. Afterward, the nanotubes were dispersed in a polyvinylidene fluoride (PVDF) matrix at various loadings of N-CNTs. The network characteristics of the fabricated N-CNT/PVDF nanocomposites were studied using imaging techniques, AC electrical conductivity, and linear and nonlinear rheological measurements. The rheological results confirmed the inability of (N-CNTs)10 to form any substantial network through the PVDF matrix. Thus, its nanocomposites exhibited an insulative electrical behavior even at high concentration of 3.0 wt%. Although the results of TEM of nanocomposites and rheological measurements represented similar ability of (N-CNTs)20 and (N-CNTs)40 to establish a continuous 3D network of N-CNTs within PVDF, (N-CNTs)40/PVDF nanocomposites showed approximately one order of magnitude higher electrical conductivity. The better electrical properties of (N-CNTs)40/PVDF nanocomposites are attributed to intrinsic chemical features of (N-CNTs)40, such as nitrogen content and nitrogen-bonding type. Taken together, the C/S ratio controls the structural and electrical properties of the N-CNTs. Hence, optimizing this ratio in CVD method can lead to a higher quality of nanomaterials for fabrication of high-performance electrically conductive polymeric nanocomposites.