We explored the effectiveness of loxoprofen sodium (loxoprofen), which is the most common non-steroidal anti-inflammatory drug (NSAID) in Japan, for patients with benign prostatic hyperplasia (BPH) complaining of nocturia. A total of 93 BPH patients aged 49-84 years were enrolled in the study. These patients had received standard drug therapy with alpha1-blocker for BPH, followed by anticholinergic drugs, hypnotics, tricyclic antidepressants, and/or antiduretic hormone, but they still complained about 2 or more episodes of nocturia. They each took a single 60-mg tablet of loxoprofen prior to sleeping at night for 14 days in addition to their BPH treatments. The effects were assessed by questionnaire before and after treatment as excellent (nocturia disappeared or decreased by 2 or more voids/night), improved (nocturia decreased by 1 void/night), unchanged, or worsened (nocturia increased). Nocturia improved or disappeared in 74.2% of patients: excellent, improved, unchanged, and worsened results were obtained in 37.6%, 36.6%, 21.5%, and 4.3% of patients, respectively. The effects were better in patients whose baseline nocturia was>> 2 times than in those with a lesser frequency at enrollment (P = 0.04). Loxoprofen can be an effective and useful treatment option for patients with BPH complaining of refractory nocturia.