A new procedure for the extraction of tissue monoamines combines the homogenization and butanol extraction steps. In addition to the significant reduction in the time necessary for extraction which is characteristic of single-extraction procedures, greater extraction efficiencies are obtained. Hence, the absolute amount of amine available for spectrophotofluorometric determination is greater and the potential error arising from correction for losses during extraction is reduced. The procedure has been routinely employed in this laboratory for more than 2 years, and has proven to be reliable.