150 patients scheduled for elective abdominal hysterectomy,were randomly divided into three groups. 10mins before spinal anaesthesia, Group “O” wasgiven 4mg ONDANSETRON  ,group “P” received  PALANOSETRON 75 microgram , group “S” received normal saline; over 5mins. Mean arterial blood pressure, heart rate, nausea, shivering, bradycardia and requirement of vasopressor were assessed. The fall inmean arterial pressure was least in “O” group, followed by “P” group and “S” group. Nosignificant difference was observed regarding heart rate. Group “O” & “P” had significantly lower requirement of vasopressor .