The VR-1 reactor operated by the Czech Technical University in Prague was utilized for a study of a macroscopic cross-sections homogenization performed by deterministic (SCALE 6.1.2 — Triton) and stochastic (Serpent 2.1.24) codes. These cross-sections are subsequently imported into a fixed source problem solved by the three-dimensional reactor core simulator PARCS v3.2. PARCS solves the steady-state and time-dependent, multi-group neutron diffusion and low order transport equations. All multiplication factors provided by each code are compared and discussed. Due to the small size of the core, all elements are more closely coupled by neutron fluxes in surrounding positions; therefore homogenization must be conducted in properly chosen volumes to respect all effects of a spatiality.