57°46′11″N 12°01′04″E / 57.76961°N 12.01787°E / 57.76961; 12.01787 Lärjedalen is in the south of the former municipality Angered; it gets its name from the river Lärjeån that crosses the municipality.

Great parts of Lärjedalen are natural reserves.

The "center" of Lärjedalen is the suburb Hjällbo.