Understanding how individual body size is affected by habitat quality allows us to assess the consequences of habitat loss and fragmentation on the morphology of arthropods. In this study, we examined the effect of habitat quality (litter depth and dry mass, understory density, canopy openness, and diameter at breast height of trees) on the body size of the litter dwelling scorpion Tityus pusillus Pocock, 1893 in fragmented rainforests of Brazil. The study was performed during the dry season in 10 forest fragments, and scorpions were collected with the aid of ultraviolet light lamps. Females, but not males, responded to the environmental attributes measured. Litter dry mass was positively related to individual body size of T. pusillus. These results suggest scorpion body size is sensitive to habitat structure. Environmental characteristics determine specific ranges of body size in scorpion populations, wherein smaller individuals inhabit sites that have less litterfall.