Various plasma process parameters such as coupled power, process pressure (p), gas flow, and source gas ratios (SiH4:H2) play crucial roles in determining the size and crystallinity of the synthesized Si nanoparticles (NPs). One of the less studied parameters for NP growth is the inter-electrode distance, d. Our study focuses on the effect of d and demonstrates how a reactor with larger d (refers to d = 30 mm) is a simple method to enhance the crystalline ratio of NPs produced in them compared with a standard d (refers to d = 10 mm). Increasing d or p is not strictly equivalent, and we show that for our reactor p > 0.8 mbar is most effective at d = 30 mm to obtain purely crystalline NPs. We also establish how the larger d opens up a wider parameter space for the synthesis of crystalline Si NPs. Completely crystalline silicon NPs synthesized in this study at p = 0.8 mbar and larger d of 30 mm. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim