Objective: There is still controversy about the feasibility and long-term outcome of surgical treatment of acquired diaphragm paralysis. We analyzed the long-term effects on pulmonary function and level of dyspnea after unilateral or bilateral diaphragm plication. Methods: Between December 1996 and January 2006, 22 consecutive patients underwent diaphragm plication. Before surgery, spirometry in both seated and supine positions and a Baseline Dyspnea Index were assessed. The uncut diaphragm was plicated as tight as possible through a limited lateral thoracotomy. Patients with a follow-up exceeding 1 year (n = 17) were invited for repeat spirometry and assessment of changes in dyspnea level using the Transition Dyspnea Index (TDI). Results: Mean follow-up was 4.9 years (range 1.2-8.7). All spirometry variables showed significant improvement. Mean vital capacity (VC) in seated position improved from 70% (of predicted value) to 79% ( p < 00.03), and in supine position from 54% to 73% ( p = 0.03). Forced expiratory volume in 1 s (FEV 1 ) in supine position improved from 45% to 63% ( p = 0.02). Before surgery the mean decline in VC changing from seated to supine position was 32%. At follow-up this had improved to 9% ( p = 0.004). For FEV 1 these values were 35% and 17%, respectively ( p < 0.02). TDI showed remarkable improvement of dyspnea (mean + 5.69 points on a scale of À9 to +9). Conclusion: Diaphragm plication for single-or double-sided diaphragm paralysis provides excellent long-term results. Most patients were severely disabled before surgery but could return to a more or less normal way of life afterwards. #