The study objective was to assess the efficacy, safety and feasibility of switching from levodopa/benserazide (LB) or levodopa/carbidopa (LC) to levodopa/carbidopa/entacapone (LCE) in Parkinson's disease (PD) patients with wearing-off. This was a multicenter, open-label, 6-week study; the primary outcome was success rate based on the patient-assessed Clinical Global Impression of Change (P-CGI-C). Secondary outcomes included investigator-assessed CGI-C (I-CGI-C), change from baseline in Unified Parkinson's Disease Rating Scale (UPDRS), motor/non-motor wearing-off symptoms and quality of life-visual analog scale (QoL-VAS). After switching to LCE, 77% of patients reported an 'improvement' (p < 0.0001 vs. patients reporting 'no change or worsening'). Significant improvements were seen in I-CGI-C, UPDRS and QoL-VAS, regardless of prior therapy. Oral levodopa dosing was increased in 28% of patients; the primary outcome remained significant when these patients were excluded. The data suggest that switching from LB/LC to LCE provided a significant benefit in PD patients with wearing-off.