The Portuguese Geotechnical Society (SPG) began in the 1950s with the Soil Mechanics Commission of the Order of Engineers, which was led by Prof. Manuel Rocha. In 1955, the Commission promoted a course in Soil Mechanics, which had a great impact on the national technical environment. It was this course that established the Soil Mechanics as a discipline, in Portugal.

The Commission became independent of the Order and became the Portuguese Group for Soil Mechanics, joining the International Society of Soil Mechanics and Foundations Engineering (ISSMFE). In 1966, coinciding with the first International Congress of Rock Mechanics held in Lisbon, the Group enlarged its scope to Rock Mechanics and is now called the Portuguese Group for Soil Mechanics and Rocks, integrating into the International Society of Rock Mechanics (ISRM). In 1972, with the development of Engineering Geology, in whose International Association (IAEG) the Group also became a member, and its current designation (SPG) was adopted. In the late 1980s, SPG joined the InternationalTunnelling Association (ITA). From 2001 SPG also represents the International Society of Geosynthetics (IGS).

An important milestone for the SPG, was the inauguration of the publication of Revista Geotecnia in June 1971, which has been published uninterrupted since then. Its aim has always to been to serve as a means for communication between Portuguese speaking geotechnical engineers.

According to its statutes, SPG is a scientific association for individuals and groups of people whose purpose is:

• At national level, to promote the development of knowledge in the field of Geotechnics and to promote cooperation between entities interested in this field
• At the international level, collaborate with related foreign bodies.

In order to achieve its objectives, SPG shall:

• Organize national and international meetings, and study visits.
• Promote the dissemination of works.
• Promote national representation in international institutions and congresses of the specialty.
• Publish annually a report on the activity of SPG during the previous year and with suggestions on the activities to be carried out.

The governing bodies of SPG are the following:

• General Assembly – the body of the SPG, composed of all the members of the Society, whose work is directed by the President and a Secretary.
• Board – consists of the President, Vice-President, Secretary-General, Deputy Secretary and Treasurer.
• Fiscal Board – consists of three members, the President, Secretary and one Member.
• Advisory Board – is formed by former presidents of the SPG Board, and its President is elected from among its members.