This river flows through the municipalities of Sainte-Barbe (MRC Beauharnois-Salaberry) and Saint-Anicet, in the Le Haut-Saint-Laurent Regional County Municipality, in the administrative region of Montérégie, in Quebec, in Canada.

These two rivers take their common source from a marsh area located south of the village of Sainte-Barbe.

The La Guerre river flows in agricultural zones first towards the southwest, towards the west bypassing an area of marsh, then towards the northwest until its mouth.

It evokes the life work of "François Benoît dit Laguerre" who, at the turn of the XIXth, was building along its course.

[1] The toponym "Rivière La Guerre" was formalized on January 5, 1984, at the Commission de toponymie du Québec.