Pugwash consists broadly of two networks run by Student Pugwash USA, plus programs and events run by three more sibling Pugwash organizations:

• Student Pugwash: our flagship program of student members, generally but not always organized in chapters, holding events and taking action at their schools and universities, and on a larger interchapter scale in regional and national programs and projects.
• The Rotblat Society: our general membership program for "post-educational" members (we don't like to say "older") and Student Pugwash alumni who wish to support student programs or get involved in similar activities. In order to promote mentorship and useful networking, all Student Pugwash members are automatically members of the The Rotblat Society.

  Student Pugwash and Rotblat programs are grassroots and membership-driven, decided by the interests of our members and the chapters and ad-hoc groups they organize.

• There are other organizations in the Pugwash Movement: 
   
  • The Pugwash Conferences on Science and World Affairs, also known as "Senior Pugwash" (within Student Pugwash, anyway), is dedicated to issues of international security, especially existential and genocidal threats to humanity. We were founded to replicate their model at the student level, although in the years since we've taken on a somewhat broader topical area and operate very differently. The Pugwash Conferences manage an ongoing conference series and workshops, and maintain an international network of national Groups operating in many countries. In 1995, Senior Pugwash shared the Nobel Peace Prize with one of their co-founders and long-term President, Joseph Rotblat. Our general membership program is named in his honor and memory (and with his permission).
  • International Student/Young Pugwash (IS/YP) is the umbrella organization for all Student Pugwash groups around the world, including us. Each national group has its own character, interests, and methods of operation. 
  • The Thinkers Lodge in Pugwash, Nova Scotia is the site of the first meeting of the Pugwash Conferences, and obviously the name of the town was subsequently adopted as the name of the Conferences and all later Pugwash organizations. It is now a Canadian National Historical Site, in use as a conference venue (as well as weddings and bar mitzvahs). It hosts an excellent museum of Pugwash artifacts, including the Nobel Peace Prize medallion won by the Pugwash Conferences and Joseph Rotblat.

For historical reasons, "Student Pugwash USA" is the legal name of our 501(c)3 nonprofit, but our Student Pugwash and Rotblat Society programs are not limited to US borders. Our members outside the US are encouraged to also become involved with their local national groups and IS/YP, and all IS/YP students and alumni are welcome as members here. Our Rotblat network operates internationally wherever there is interest. If you're a citizen outside the US or living abroad, we'll connect you to IS/YP and other activities in your region.

It should be noted that colloquially, we in Student Pugwash USA frequently call ourselves "Student Pugwash" or just "Pugwash." This should not be taken to mean that we speak for any other Pugwash group, or that we coordinate them; it's just shorthand. When we're working with other Pugwash groups or otherwise in a situation where there might be confusion, we use the full name. We know this is confusing—if it's not clear which Pugwash someone is referencing, just ask.