Data are lacking regarding the use of diuretics in facilitating closure of the open abdomen (OA). For patients with an OA after 2 laparotomies, we hypothesized that diuretic use was associated with a higher rate of primary fascial closure than no diuretic use. A retrospective review of patients with trauma laparotomies over 7 years was performed. Primary fascial closure (PFC) was defined as apposition of fascial edges without interposition mesh. Of 321 patients, 30 (9%) remained with an OA after 2 laparotomies. Prior to the third laparotomy, median cumulative fluid balance was +12.6 L. Thirteen (43%) received diuretics. Primary fascial closure rates were similar for diuretic use vs no diuretic (38% vs 59%, P = .46). Primary fascial closure was not associated with age ( P = .2), gender ( P = 0.7), cumulative fluid balance ( P = .3), or units of packed cells ( P = .4). Diuretic use in trauma patients with an OA after 2 laparotomies was not associated with successful PFC.