The aim of this study was to evaluate the course of urethral obstruction in cats. Forty-five male cats with urethral obstruction or lower urinary tract signs referable to urethral obstruction were included in the study. Follow-up information was gained by telephone interview in most cases and was available in 39 cats. Of the 22 cats with idiopathic urethral obstruction, eight (36%) re-obstructed after 3-728 days (median 17 days). Of 10 cats with urolithiasis, three (30%) re-obstructed after 10, 13 and 472 days, respectively. Of the seven cats with urethral plugs, three (43%) re-obstructed after 4, 34 and 211 days, respectively. Recurrent signs of lower urinary tract disease including obstruction were common in cats with urethral obstruction (20/39; 51%) and occurred in the same frequency irrespective of the primary cause of the obstruction. Recurrent obstruction (14/39; 36%) was the most common reason for euthanasia and was performed in 8/39 (21%) cats.