Pertunmaa belongs to the province of Eastern Finland, to the region of South Savo and to East Häme as it is located in the border area between Häme and Savo. Pertunmaa is located along highway 5, approximately 35 kilometres north of Heinola. The ABC-Kuortti service station is a good landmark. Pertunmaa has two main conurbations: the parish village and Kuortti. Kuortti is the better-known of these, located along highway 5. It is Pertunmaa's calling card.
The parish village, approximately 10 kilometres from Kuortti, is a peaceful residential area with services and lake landscapes stretching right into the village centre. The parish village functions as the administrative centre of Pertunmaa.