In an observational study, we prospectively evaluated the efficacy and safety of remifentanil in 205 parturients. Remifentanil was administered as a continuous infusion. The initial infusion of 0.025 microg x kg(-1) x min(-1) was increased in a stepwise manner to a maximum dose of 0.15 microg x kg(-1) x min(-1). Maternal pain, other maternal and fetal variables, side effects, and satisfaction were recorded. The mean (+/-sd) visual analog score before the start of the infusion was 9.4 +/- 1.2 cm and decreased to 5.1 +/- 0.4 cm after 5 min and 3.6 +/- 1.5 cm after 30 min. The maternal side effects were minimal and no fetal or neonatal side effects were noted.