In pasture-based systems where seasonal calving predominates, many farmers use open dirt corrals to keep cows before calving. Our objective was to examine whether shelter provision under winter conditions influences behavior and body fat mobilization in outdoor-housed prepartum dairy cows. Two cohorts of 12 clinically healthy multiparous Holstein prepartum cows were housed in open dirt corrals at the Experimental Dairy Farm of the Universidad Austral de Chile (Valdivia, Chile) during the winter months (July and August). Twenty-one days before the expecting calving date, the cows in each cohort were paired. Each pair was randomly assigned to either a corral without shelter, or to a corral with access to an artificial shelter until calving. The use of shelter was measured by scan sampling every 10 min from video data (2 cameras/corral) during the 3 weeks study period. The lying time were measured with data loggers and rumination time was recorded using an automated monitoring system over the study period. A blood sample was taken from the coccygeal vein of each cow for measurement of nonesterified fatty acids (NEFA) the same day once a week. Daily lying and rumination time were summarized by week and comparisons were made between groups with and without access to shelter. Data were analyzed using mixed linear models (SAS v9.4). Cows spent 62% of their daily time in the shelters and 75% of this time they were lying down. Furthermore, the cows that had access to shelter during the prepartum spent more time lying down during the wk 3(706 min/d vs. 559 min/d; P < 0.001) and wk 2 (742 min/d vs. 566 min/d; P < 0.001) before calving compared with cows without shelter access. They also had lower NEFA concentrations on wk 2 (272 µmol/L vs.554 µmol/L; P < 0.001) and wk 1 (460 µmol/L vs. 646 µmol/L; P = 0.05) before calving. The daily rumination time was not different between groups. These results demonstrate the importance of granting a protected area for the welfare of prepartum dairy cows exposed to winter climate conditions. Project funded by FONDECYT #11170820.