Tiestall dairy cows spend their whole days in the same space, which, therefore, must be designed to accommodate all the activities they conduct. Lying is a very important behavior for dairy cows and a critical response variable for assessing stall designs, to ensure that their needs for resting space are met. The objective of this study was to determine if increasing tie-stall width alters the lying behavior of lactating dairy cows. Two treatments were compared: the current recommendation (139 cm) and a double stall (284 cm). Stall length was of 188 cm. Sixteen cows were blocked by parity and lactation stage, then randomly allocated to a treatment and a stall within 1 of 2 rows in the barn, for a period of 6 wk. Leg-mounted accelerometers were used to record lying behaviors. Cows were recorded on video one full 24h/wk, using surveillance cameras positioned above the stalls. Video data from wk 1, 3 and 6 were recorded at a rate of 1 frame per minute, and analyzed by a trained observer to assess the position and the location of the cows’ body, head, and limbs during the lying hours. Lying behaviors, and frequency of each position and location were analyzed in SAS using a mixed model in which treatment, block and week were included as fixed factors, and cow and row, as random factors. Multiple comparisons were adjusted for using the Scheffé method. Results indicate that cows in the double stalls fully extended their hindlimbs more often than the control cows (21.7% vs 7.64%, P = 0.015). They also intruded in the neighboring stalls with their hindlimbs less often than the control cows [2.39 vs 16.3% for the left side (P = 0.0004), 0.14 vs 13.1% for the right side (P = 0.0045)], instead favoring the second half of the double stall, in 38.3 ± 6.37% (P = 0.0039) and 29.2 ± 6.57% (P = 0.012) for the left and right hind legs, respectively. Total lying time did not differ (P = 0.24) between the double stall group (716.1 ± 25.04 min/d) and the control group (670.8 ± 24.98 min/d). These results suggest that dairy cows utilize the additional space they are granted with, and that they would likely benefit from stall widths larger than what is currently recommended for tiestall and freestall systems.