The lands of Boimorto belong to what in Galicia are called mountain lands. They have a rolling relief, without real mountain ranges or high peaks. The altitude ranges from 614 metres at Coto de Salgueiros, in the south of the municipality, to the banks of the Tambre in the north, which runs at just over 400 metres.

The exception is the eastern corner, which climbs the slopes of the Bocelo hills up to 733 metres at Coto das Amieiras.

The area is 82.6 square kilometres and the population was 3,003 (1986 census). Its density of 36.35 inhabitants per square kilometre is among the lowest in the province of A Coruña.

As for its rivers, the municipality of Boimorto sits on a series of ridges that divide the basins of the Tambre and the Ulla.

The Tambre forms its northern boundary with the municipality of Présaras, with natural spots of great interest such as the muíños (water mills) of Valdoña, the old Mezonzo power station, where the river Cabalar flows in, and the ruins of the Présaras textile mill.

Its economy is almost entirely farming and livestock, and it is among the areas of A Coruña that need special attention to encourage their development.