The trial was designed as an open-label, post-authorisation safety study, aimed to complete the available information on adverse events and drug reactions to alpha-dihydroergocryptine (CAS 14271-05-7, alpha-DHEC). The study included 294 patients with idiopathic Parkinson's disease who received levodopa (CAS 59-92-7, L-DOPA) and started taking alpha-DHEC (Cripar). Adverse events were analysed descriptively, Parkinson's disease symptoms were documented using a questionnaire applied by the physicians. Patients were evaluated at study start and three and six months later, respectively. In 31 patients, 32 adverse events were observed, gastrointestinal and nervous system disorders being the most frequent. Dyskinesias, psychoses/hallucinations, sleep disturbances, and cardiovascular disorders were uncommon (< or = 1%). in total, 21 adverse events were classified as adverse drug reactions. In nearly 80 % of the cases, Parkinson symptoms had improved or completely vanished. Symptoms were unchanged in 16.7 % of patients and had worsened in 3.1%. The results confirm that the use of alpha-DHEC in combination therapy with levodopa in patients with Parkinson's disease is a well-tolerated and efficacious treatment option.