Sow housing is the most controversial welfare issues facing the swine industry. We hypothesize that slight modifications of the stall may influence sow well-being, thus the objective was to evaluate the effects a modified gestation stall has on behavior and productive performance of dry sows. On d 23±5 of gestation 16 multi-parious sows were allocated to either a standard stall (CRATE) or adjustable stall (width only; FLEX); fixed dimensions for CRATE; 55.9cm × 218.4cm and FLEX; 48cm × 215.9cm. For sows in FLEX, once placed in the stall, width was adjusted based on sow body size to achieve 2cm of space between bottom bar and sow's udder while lying in full lateral recumbency at early-gestation, mid-gestation, and late-gestation. Widths were 51.9±0.56 (early-gestation), 57.8±0.64 (mid-gestation), and 62.3±0.61 (late-gestation); length was constant. Behavior was registered using continuous video-records. Lesions were recorded on d 25±5, 45±5, and 112±5 of gestation. Data were analyzed using Proc MIXED with repeated measures (SAS). Sows in CRATE performed more oral-nasal-facial (111.5min) and sham-chewing (98.8min) than sows in FLEX (53.8min; 57.5min, respectively, P<0.0001). Sows in CRATE also performed more of these sterotypies later in gestation (174min) than sows in FLEX (59.6min, P<0.0001). Sows in FLEX sat more (187.5min) than sows in CRATE (68.7min, P<0.05). Sows in CRATE tended to drink more (44.5min) than sows in FLEX (34min, P<0.10). Lesions (right side) were greater among sows in FLEX (10.8) than sows in CRATE (7.7, P<0.05), but lesions decreased from gestation d25 (24.1) to d112 (14.1) among all sows (P<0.05). Sows in FLEX had more piglets born (14.3, P<0.01) and tendency for more piglets born alive (12.9, P<0.10) than sows in CRATE (11.3 and 10.3 respectively, P<0.01). These data indicate that a slightly modified stall can affect stereotypic behaviors, lesions and productivity of the sow, thus potentially enhancing welfare.