Helping women to stop smoking during pregnancy is a major priority for health professionals and evidence suggests that financial incentives can be effective. With the aim of maximising the benefits and minimising unintended negative consequences, this paper gives a brief review of evidence about using financial incentives for smoking cessation during pregnancy, with a special emphasis on how financial incentives work. The review showed that financial incentives can increase pregnant women’s capability, opportunity and motivation to stop smoking. The evidence supports five specific recommendations about how financial incentives should be used in future to reduce smoking during pregnancy, including measures to increase public acceptability. These recommendations can contribute to updating published UK policy for smoking cessation during pregnancy, including the National Institute for Health and Care Excellence (NICE) guideline on stopping smoking in pregnancy and after childbirth (PH26).