The Naturalistic Section of the Civic Museums of Bassano del Grappa preserves collections of ancient and recent natural history. The historical, geological, and botanical collections date back to the years of the museum's foundation, when the geologist and naturalist from Bassano, Giambattista Brocchi, in 1828, bequeathed his geo-paleontological collections, library, and manuscripts to the City of Bassano, so that the Civic Museum could be established. His student and collaborator, the botanist from Bassano, Alberto Parolini, also donated his geological collections, herbarium, library, and manuscripts to the museum upon his death in 1867. This initial core was then expanded with the herbarium of the pharmacist and botanist from Bassano, Giovanni Montini, a collaborator of A. Parolini. In recent times, at the end of the last century, the entomological collections of Ferruccio and Mario Meneghetti were added through donation, and recently, the Luca Cites collection has enriched the museum with a zoological collection featuring numerous mammals and birds. The museum also houses smaller naturalistic collections (in terms of quantity, not importance) of shells (H. Nisters' malacological collection), dragonflies, other herbaria, and a small but significant zoological collection of rare mammals, belonging to species on the brink of extinction, entrusted to the museum on permanent loan by the Cites Service of the State Forestry Corps.

The collections of natural history, especially the historical ones, have undergone various conservation events over the course of almost two centuries since the museum's foundation, ranging from valorization to disinterest and total abandonment and degradation, also due to the tragedy of the bombing on Bassano, in which the museum was also involved during World War II. The damaged collections (especially the herbaria) from the bombings and subsequent neglect in conservation have not been exhibited to the public until today.