The first chapter of Pi Sigma Alpha was founded in 1920 at the University of Texas at Austin, and the society has grown over the years to nearly 850 campuses (as of 2020).

A local chapter may be established at any college or university granting the baccalaureate or higher degrees, which is accredited by a regional or national accrediting association, and which offers a major sequence of courses in political science through an appropriate administrative department, school, or division of the institution, and which conforms to other requirements established by the Executive Council of the society.

Student membership is open to juniors, seniors and graduate students currently enrolled in institutions where the chapters are located, who meet the following qualifications: Faculty in political science departments where chapters are located are automatically eligible for membership in the honor society.

Members of the Council are almost always faculty of recognized distinction in the field of political science, or of proven leadership to the honor society.

[3] Pi Sigma Alpha has programs to benefit its student members and their chapters, and the profession of political science.