A number of different transfection reagents have been used for lentiviral vector production. We directly compared transfection buffers, DNA purification methods, chemical facilitators, and DNA concentrations to optimize production. The use of N,N-bis (2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), sodium butyrate, and one fourth the total amount of DNA used in standard transient transfection protocols were the best conditions for virus production. These reagents were combined into a single protocol and scaled-up to produce liter quantities of virus in a multitray tissue culture vessel.