The objective was to determine the efficacy and optimal dose of sucrose for relieving procedural pain in neonates. Data were obtained using MEDLINE, EMBASE, Reference Update and personal files and assessed for quality of the methods. Data from all randomized controlled trials where term and preterm neonates received a heelstick or venipuncture were examined for the efficacy of different sucrose doses (0.18 g, 0.24 g, 0.48 g or 0.50 g, 1.0 g) and water (placebo). The primary outcome was the proportion of time crying during 3 min after the painful stimulus. Data were combined across studies using a random effects model, adapted for use with single groups, producing a point estimate and 95% confidence interval (CI). Thirteen trials were identified; eight were rejected as data were inappropriate, non-extractable, or the primary outcome was not measured. Five studies provided data on 271 infants. The proportion of time crying did not differ between 0.18 g of sucrose and water (p > 0.05) but was significantly lower in all other sucrose groups. There were no differences in proportion of time crying between term and preterm neonates. Sucrose reduced the proportion of time crying during painful procedures in neonates. The 0.18 g dose of sucrose was ineffective. Doses of 0.24 g (2 ml of 12% sucrose solution) were most effective. A dose of 0.50 g provided no additional benefit.