Aim: Electrocautery is proved to be associated with increased seroma during mastectomy. This study aimed 
at comparing mastectomy using harmonic scalpel versus electrocautery and whether the harmonic scalpel is 
cost effective or not؟
Methods: This study included sixty females undergoing modified radical mastectomy .Thirty were operated 
with harmonic scalpel and thirty with electrocautery .We compared operative time, blood loss, total 
drainage volume and days, pain score, total dose of nalbuphine and incidence of sermoa, hematoma and
flap necrosis.
Results: There was no statistical difference between two groups as regard operative time (P=0.12), seroma 
(P=0.2), hematoma (P=0.7) and flap necrosis (P=1). There was a highly significant difference (P<0.001) 
regarding blood loss, total drainage volume and days, pain score and the total dose of nalbuphine. Hospital 
stay was not shortened because all patients were routinely discharged after three days.
Conclusion: Harmonic scalpel in mastectomy significantly reduces blood loss, postoperative pain, total 
drainage volume and days but does not lower operative time, seroma, total hospital stay and till now cannot 
be considered cost effective.