The purpose of this study was to estimate the net economic cost or benefit of pretreating women who have a medical indication for induction of labour, and an unprepared (unripe) cervix, with a manufactured dinoprostone (prostaglandin E 2) gel. Findings of a meta-analysis of the results of 3 large, randomised clinical trials were employed in the construction of a decision tree used in the economic analysis. For the intended target population, the primary clinical and economic outcomes of gel pretreatment were shortening of the treatment-to-delivery interval, an increase in the percentage of patients achieving labour and a decrease in the percentage of patients requiring delivery by caesarean section. Application of cost factors associated with these and other variables led to a finding of net savings associated with use of the dinoprostone gel pretreatment, compared with no gel pretreatment, of $US159 to $US214 (1993 prices) per treated patient, corresponding to the maximum and minimum duration of the pre-induction treatment period, respectively.