In this chapter, we provide an account of the professional responsibility model of obstetric ethics, and identify its implications for two major topics: patient-choice caesarean delivery and trial of labour after caesarean delivery. The professional responsibility model of obstetric ethics is based on the ethical concept of medicine as a profession and the ethical principles of beneficence and respect for autonomy. The obstetrician has beneficence-based and autonomy-based obligations to the pregnant woman and beneficence-based obligations to the fetus when it is a patient. Because the viable fetus is a patient, the ethics of caesarean delivery requires balancing of obligations to the pregnant and fetal patient. The implication of the professional responsibility model for patient-choice caesarean delivery is that the obstetrician should respond to such requests with a recommendation against non-indicated caesarean delivery and for vaginal delivery. These recommendations should be explained and discussed in the informed consent process. It is ethically permissible to implement an informed, reflective decision for non-indicated caesarean delivery. The implication for trial of labour after caesarean delivery is that, in settings properly equipped and staffed, the obstetrician should offer both trial of labour after caesarean delivery and planned caesarean delivery to women who have had one previous low transverse incision. The obstetrician should recommend against trial of labour after caesarean delivery for women with a previous classical incision.