Inclusion Criteria:  A total of one hundred and fifty parturients in child bearing period (20-40 years), with BMI of 23-27, and ASA physical status II, who were candidate for elective caesarean section, were enrolled in this prospective randomized study.  Exclusion criteria  Exclusion Criteria:  1 - Lady refusal to participate. 2. All pregnant women candidate for emergency caesarean section elligible for general anaesthesia (GA).  3.presence of any contraindications of dexamethasone (as DM and uncontrolled infection ) or any contraindication of ondansetron (as prolonged QT interval 6. Presence of cardiac, respiratory, hepatic, renal and mental diseases. 7. Coagulopathy, or any contraindication to spinal anaesthesia. 8. Presence of complicated pregnancies (such as pregnancy induced hypertension, placenta previa or eclmpsia).