The PTS started its work in Vienna on 17 March 1997 under the auspices of Executive Secretary Wolfgang Hoffmann. On 1 August 2005, Tibor Tóth became the Executive Secretary of the Preparatory Commission. The Executive Secretary is the only PTS official appointed by the Commission and reports directly to the Commission on PTS operations.

The main function of the PTS is to assist the Preparatory Commission in the establishment of a global verification regime to monitor compliance with the comprehensive ban on explosive nuclear testing. This regime – sometimes referred to as a "global alarm system" – is being built up so that it will be operational as soon as the Treaty enters into force. Another PTS function is to promote the signing and ratification of the Treaty so that it enters into force as soon as possible.

The PTS staff is multinational in composition. However, only nationals of Signatory States are eligible to serve in the PTS.

The Organization considers its staff and their expertise to be its most important resource. The PTS is a non-career organization which means that there are limitations on the number of years that Professional staff may serve there.

There are two main categories of PTS staff:

Professional and General Service Staff.