BACKGROUND: Clinical practice in Russia is set out in a series of centralized guidelines. However, many of these guidelines are not supported by evidence and, despite their existence, there is considerable unexplained variation in practice. This study examines the decision to recommend a Caesarean section, an intervention for which there is a solid evidence base, but whose use varies considerably among facilities in Russia. AIM: To identify the factors that Russian obstetricians take into account when recommending a Caesarean section. METHODS: Conjoint analysis. Ninety-two obstetricians from three regions were asked to state whether they would recommend a Caesarean section in each of 30 vignettes (including three for validation) combining 10 medical, social and organizational factors previously identified as contributing to the decision to intervene, including some absolute indications to intervene or not to, on the basis of international evidence. RESULTS: Checks for consistency within ratings by individuals gave no cause for concern. However, there was a wide variation in the probability of intervening among obstetricians, with six recommending intervention in only one scenario and one in 27 scenarios. Some factors were consistent with evidence but others were not, such as myopia or previous abortions. INTERVENTION: was more likely at 11 p.m. than at noon. Male obstetricians were more likely to intervene than females. CONCLUSION: This study highlights the importance of understanding clinical decision-making in Russia as a prelude to changing it.