BACKGROUND Electronic fetal monitoring (EFM) has been widely adopted. There is debate about its overall effectiveness as well as the relative merits of routine application versus use for high-risk pregnancies only. OBJECTIVE The objective of this review was to assess the effects of routine continuous electronic fetal monitoring during labour compared with intermittent auscultation. METHODS We searched the Cochrane Pregnancy and Childbirth Group trials register, Medline (1966 to 1994), and reference list of relevant articles. We also contacted experts in the field. METHODS Randomised trials comparing routine continuous electronic fetal monitoring with intermittent auscultation. METHODS Data were extracted by one reviewer, and their accuracy was confirmed independently by a second person. A single reviewer assessed study quality based on criteria developed by others for randomised controlled trials. Data reported from similar studies were used to calculate a combined risk estimate for each of eight outcomes. RESULTS Nine studies involving 18,561 women and their 18,695 infants were included. The trials were of variable quality. A statistically significant decrease was associated with routine continuous EFM for neonatal seizures (relative risk (RR) = 0. 51, confidence interval (CI) = 0.32,0.82). The protective effect for neonatal seizures was only evident in studies with high-quality scores. No significant differences were observed in 1-minute Apgar scores below 4, 1-minute Apgar scores below 7, rate of admissions to neonatal intensive care units, and perinatal death. An increase associated with the use of EFM was observed in the rate of cesarean delivery (RR = 1.41, CI = 1.23,1.61) and operative vaginal delivery (RR = 1.20, CI = 1.11,1.30). CONCLUSIONS The only clinically significant benefit from the use of routine continuous EFM was in the reduction of neonatal seizures. In view of the increase in cesarean and operative vaginal deliveries, the long-term benefit of this reduction must be evaluated in the decision reached jointly by the pregnant woman and her clinician to use continuous EFM or intermittent auscultation during labor.