Objective: To study the physiological and behavioral response to pain.Methods: 80 healthy neonates requiring bilirubin estimation, blood sugar etc. were randomly assigned to receive a venous puncture. All parameters were recorded 10 minutes prior, during and 10 minutes after the procedure. Evaluated NIPS score and RR., HR, NIBP and 02 saturation observed on Datex-Ohmeda multimonitor.Results : After the venepuncture, heart rate (p<0.001 ) and blood pressure (p<0.001 ) were significantly increased in both the groups but more significant increase was present in Group l(>2.5kg) as compared to Group II (>2.5kg). Respiratory rate was also increased but more significant in Group II(p<0.001) whereas Oxygen saturation was decreased in both the groups but more significant in Group I (p<0.001). Median Neonatal Infant Pain Scale (NIPS) score was higher in both the Groups (p<0.001 ).Conclusion : The outcome measures appear to be reliable indices of term neonates responses to painful stimulation. NIPS are suitable instruments for neonatal pain evaluation.