Comfortable flooring may impact many aspects of an animal’s welfare, including lying behavior, an animal’s ability to change postures, and incidence of lameness and lesions. Therefore, we hypothesized that the addition of rubber mats to stalls of group pens would improve sow health, comfort and welfare during breeding. In this study, Landrace X York-Yorkshire sows (128) were mixed post-weaning and housed in pens of four. The pens contained a slatted group area and four feeding stalls. Rubber mats (measuring 1.83m X 0.61m X 1.27 cm) were added to the feeding stalls of half of the pens and rotated to the opposite pens for each replication. The behavioral time budgets of the sows were recorded throughout the experiment; lesion and lameness scores were collected prior to mixing and at the end of the experiment. Data were analyzed as repeated measures mixed models with post hoc Tukey tests. The pattern of behaviors performed in the stall versus group area was different for mat and concrete treatments. Tukey tests revealed that only resting behaviors were affected. We then examined resting behavior in detail. Time spent in different resting postures (sternal versus lateral lying) differed between treatments, where sows on mats spent more time lying laterally and performed more of their lying behavior in the stalls compared to sows on concrete. Additionally, sows stood up and laid down more frequently than sows on concrete. Warm temperatures reduced resting behavior in the stalls. Sows in matted pens had a lower total lesion score at the end of the experiment in comparison to sows in concrete pens. Lameness scores did not differ between treatments. These results imply that the provision of alternative comfort flooring may provide welfare benefits to breeding sows, though environmental temperature needs to be considered when providing rubber mats.