PSI is a voluntary body composed of special interest groups (SIGs) and committees charged with the running of the society's affairs. Their activities are overseen by the Board of Directors whose members are elected for two year terms. This structure is laid out below.

The society holds an annual general meeting, generally during its annual conference. Minutes from previous AGMs and the annual accounts are archived on this site for members.

The BoD, committees and SIGs run PSI in line with PSI's Articles of Association with a business plan  updated on a three-year cycle.