The main objective of the present work is to compare the influence of silica-coated nano calcium carbonate (SNCC) with uncoated nano calcium carbonate (NCC) as filler on the property enhancement of polychloroprene rubber (CR) composites. The CR nanocomposites containing SNCC exhibit superior curing, mechanical and thermal properties in comparison to NCC-filled CR nanocomposites. The fantastic enrichment in the resulting properties of CR nanocomposites containing SNCC is mainly due to better rubber–filler interaction resulting from the reasonably excellent dispersion of SNCC within the CR matrix. The more uniform distribution of SNCC in comparison to NCC within the rubber matrix is also confirmed from morphological analysis. Thus, in this article, we report SNCC as a new type of efficient filler to reinforce the ultimate properties of CR nanocomposites for the first time.