The Breast Surgery International BSI is an Integrated Society of the International Society of Surgery ISS/SIC. Membership application for BSI therefore has to go through the application process of ISS/SIC membership. Do not forget to indicate in the ISS/SIC application process that you wish to become BSI member as well.
The application form for ISS/SIC & BSI membership can be found at:
The Link below leads you to the Membership Directory of the International Society of Surgery which includes BSI members. To seek specifically for a BSI Member in your country, select your country and Integrated Society BSI and submit your request.