The jaguar (Panthera onca) represents the largest felid in the Americas and the third-largest in the world. Historically, jaguars ranged from southern United States to Argentina, but with declining populations throughout its shrinking range, it is has been threatened with extinction. Despite its status, little ecological data exists on jaguar populations throughout its range. I initiated a study to describe movement patterns, range size, and habitat use of jaguars in the Chaco and Pantanal regions of Paraguay. Seven jaguars were trapped using trained hounds and GPS-radio collars were attached for 1 year. GPS collars were designed to acquire geographic fixes every 2.4-4 hours. I obtained >7,000 fixes from the 7 jaguars with an acquisition rate of 43%. Annual ranges varied greatly between the jaguars (MCP-95%: 77-1,705 km²) where jaguars in the Chaco (low resources) had larger ranges than in the Pantanal (high resources). On average, the jaguars moved 4.4 km/day, doing more so during the night. Jaguars in the Chaco moved on average 5.1 km/day, while in the Pantanal jaguars moved 2.7 km/day. Coincidently, the jaguar with the largest range and movement rate resided in a highly fragmented area surrounded by suburban development. This is the first report on movements and range sizes of jaguars in the Chaco. Moreover, my data illustrates the effects of landscape fragmentation on jaguar ranges and movements.