Aims: To assess the maternal and fetal acceptability of buprenorphine and neonatal abstinence syndrome (NAS) in children born to buprenorphine-maintained mothers. Design and setting: Open-label, flexible dosing, inpatient induction with outpatient maintenance, conducted at the University of Vienna within the existing pregnancy and drug addiction program. Participants: Fifteen opioid-dependent pregnant women. Intervention. Sublingual buprenorphine tablets (1-10 mg/day). Measurements: Mothers: withdrawal symptoms (Wang Scale), nicotine dependence (Fagerstrom Scale: FTQ) and urinalysis. Neonates: birth outcome and NAS (Finnegan Scale). Findings: All subjects were opioid-, nicotine- and cannabis-dependent. Buprenorphine was well tolerated during induction (Wang Score \< = 4) and illicit opioid use was negligible (91% opioid-negative). All maternal, fetal and neonatal safety laboratory measures were within normal limits or not of clinical significance. Mean birth outcome measures including gestational age at delivery (39.6 ± 1.5 weeks), Apgar scores (1 min = 8.9; 5 min = 9.9; and 10 min = 10), birth weight (3049 ± 346 g), length (49.8 ± 1.9 cm) and head circumference (34.1 ± 1.8 cm) were within normal limits. The NAS was absent, mild (without treatment) and moderate (with treatment) in eight, four and three neonates, respectively. The mean duration of NAS was 1.1 days. Conclusions: Buprenorphine appears to be well accepted by mother and fetus, and associated with a low incidence of NAS. Further investigation of buprenorphine as a maintenance agent for opioid-dependent pregnant women is needed.