Soybean meal (SBM) is referred to as the “gold” standard of protein, as other oilseeds are compared to it due to its superior quality; however, SBM also contains antinutritional factors that have been shown to hinder bird performance. Soybeans are toasted during manufacture, but the optimal temperature and holding time to ensure adequate processing is not well defined. An initial companion experiment (paper 1; Laboratory Assays Do Not Consistently Indicate Under Processing of Soybean Meal that Negatively Impacts Broiler Performance) determined that including under processed SBM in mash diets hinders bird performance. Therefore, a follow up study was performed with the objective of examining assay variation within and across laboratories of diets containing under- and peak- processed SBM conditioned at 70, 80, or 90? for 30 seconds in addition to an over-processed SBM mash diet and determining the optimal conditioning temperature via live bird performance and amino acid digestibility. The three SBM types (under-, peak-, over-processed) were obtained from a commercial soybean crush plant. Three diets were formulated to 85% crude protein and digestible amino acid requirements, differing only in the type of SBM. The under and peak diets were steam conditioned at 70, 80, or 90? prior to pelleting. The over-processed diet remained in mash form. Diets were fed for 18 days and contrasts were performed to explore differences between treatments. A 2 (SBM type) × 3 (Conditioning temperature) factorial was analyzed for the pelleted diets. The 7 diets were each fed to 12 replicate cages of 9 chicks. On day 18, live performance metrics were measured, and ileal contents were collected. Results from day 0-18 feed intake (FI) per bird increased with increasing conditioning temperature (P < 0.05). There was a soybean meal type and conditioning temperature interaction. Birds fed the under processed SBM diet gained more weight with increasing conditioning temperature while live weight gain (LWG) decreased for the peak processed diet (P < 0.05). Increasing the conditioning temperature of the under-processed SBM diet to 80? restored LWG to that of the peak processed 70? diet. Feed conversion ratio of birds fed the peak diet increased with increasing conditioning temperature while the FCR for the under diets was reduced (P < 0.05). Birds fed the over-processed SBM diet gained the least and had the lowest FI (P < 0.05). The digestibility of all amino acids increased when the conditioning temperature of the under-processed diet increased from 70? to 80? (P < 0.05) and did not change for the peak-processed diets. Diets containing under-processed soybean meal conditioned above 70°C and pelleted mitigated antinutritional performance effects.