This study describes the development work to shorten the monoclonal antibody (mAb) production time in CHO cell cultures from 14 days to 8 days without impacting mAb titer or product quality. The proposed process increases cell inoculation densities up to 25× higher than a typical seeding density in the final production bioreactor, with the implementation of an ATF™ perfusion system in the N − 1 stage. Similar antibody titer and N‐glycosylation profiles were reached in 8 days using the 25× seed condition, as in 14 days using the 1× seed condition. Acidic variants in the 25× seed condition were 12–20% lower than the 1× seed condition. These results indicate that an accelerated 8‐day antibody production process utilizing a 25× seeding strategy has the potential of achieving similar product quality and titer as the 1× seeding condition in a 14‐day production process. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:829–832, 2013