Quantitative assessments of home-range dynamics and movements of long-tailed weasels (Mustela frenata) are lacking, in spite of the importance of these data to understanding how habitat fragmentation influences behavior, ecology, and interspecific interactions. During autumn to late winter 1998–2000, we monitored 11 long-tailed weasels (7 male, 4 female) via radiotelemetry to examine home-range dynamics and movement rates in an Indiana landscape fragmented by agriculture. Mean (± SE) 95% adaptive kernel contour area for adult females and adult males was 51.8 ± 8.1 ha and 180.3 ± 60.3 ha, respectively, and differed significantly. Hourly rate of movement for male long-tailed weasels (130.5 ± 12.7 m) was greater than that of females (79.2 ± 13.5 m). Weasels demonstrated greater hourly rates of movement during the fallow season (138.2 ± 12.8 m) compared with the preharvest season (63.0 ± 11.2 m). Mean hourly rates of movement were lower in corridors, forest patches, and grassland patches compared to crop fields. Mean hourly rate of movement was positively related with home-range size (P < 0.001) with the greatest rates of movement in the largest home ranges. Mean hourly rate of movement varied inversely with prey biomass (P = 0.07). Our results are consistent with the notion that long-tailed weasels may be sensitive to agriculturally induced fragmentation of habitat and the importance of maintaining landscape connectivity for species conservation.