Soybeans [Glycine max (L.) Merr.] with the Optimum(TM)GAT(TM) trait have dual mode of action herbicide tolerance to glyphosate (N-phosphonomethyl glycine) and acetolactate synthase (ALS) inhibitor herbicides. High levels of tolerance were observed when soybean lines with the Optimum(TM) GAT(TM) trait were sprayed at different growth stages using different formulations and rates of glyphosate, ALS inhibitor, and glyphosate plus ALS inhibitor herbicide combinations. Positive and negative near-isogenic lines (NILs) created from multiple transgenic events were yield tested from 2004 to 2006. Across the events tested, yield of NILs with the OptimumTM GATTM trait were not significantly different compared to sister NILs without the Optimum(TM) GAT(TM) trait. Event DP356043-5 was selected as a lead event and BC1F3 lines were created by backcrossing DP356043-5 into four different conventional lines. Across these four backcross populations, lines with the OptimumTM GATTM trait were not significantly different for yield compared to negative sister lines. Based upon multiple year experiments, the Optimum(TM) GAT(TM) trait confers a high level of tolerance to glyphosate and ALS inhibitor herbicides with no yield impact.