Trimstein is a former municipality in the Bern-Mittelland administrative district in the Canton of Bern in Switzerland . On 1 January 2013 the former municipality of Trimstein merged into the municipality of Münsingen .

Until 1993 Trimstein was part of Rubigen .

Trimstein had an area of 3.63 km2 (1.40 sq mi). As of 2012, a total of 2.95 km2 (1.14 sq mi) or 81.3% is used for agricultural purposes, while 0.46 km2 (0.18 sq mi) or 12.7% is forested. Of the rest of the land, 0.23 km2 (0.089 sq mi) or 6.3% is settled (buildings or roads).