Diphemanil methylsulfate (Prantal) is a quaternary ammonium with parasympathicolytic properties. It is used in premature and term neonates with bradycardias related to vagal hyper reflectivity (HRV). OBJECTIVES: To assess the use of Prantal in the French neonatal and intensive care units: its indications, its modalities of use, its side effects and the number of patients treated during 1 year (2004) in France. METHODS: A questionnaire was electronically sent to all neonatology units and all neonatal intensive care units in France. RESULTS: Among 202 units, 121 (60%) answered the questionnaire. Prantal was reported to be used in 51 (42.1%) units. Among them, 38 (31.4%) actually treated 169 patients in 2004 with a mean number of patients treated by unit of 4. The diagnostic of HRV was supported by: a history of malaise (84.3%), bradycardia (94.1%), oculocardiac reflex (74.5%), cardiac Holter (76.4%), cardiorespirographic recording (19.6%), esophageal pHmetry (35.2%) and esophageal fibroscopy (21.5%). The mean starting dosing was 4.7 mg/kg/d, the mean maximal dosing was 9 mg/kg/d and the mean daily intakes were initially 2.3 and secondary 2.9. Prantal dosing was adjusted to weight in 54.9%, every month in 85.7%. Treatment was stopped at the mean post-natal age of 6 months, mostly in a progressive manner and without monitoring help. CONCLUSION: Prantal was seldom used in 2004 in France for different reasons: HRV is an uncertain entity, the efficacy of Prantal has not been validated and atropinic side effects can be encountered.