The subject of this paper is the study of the elections of the Greek parliament for the period 1981-90. We examine the existence of the neighbourhood effects of the electoral constituencies. Also we examine the phenomenon of the nationalization of the vote. For these purposes, we use a diagrammatic representation of the electoral outcomes, in triangles. We give to the triangles certain geometric properties, of the triangles and apply them on the study of the electoral changes. The results are that there exist certain geographical patterns of constituencies, which have common "behaviour", and also that there exists a tendency for the nationalization of the vote.
