A high-performance liquid chromatographic method using solid-phase dansylation on alumina for precolumn fluorescence label has been developed for the determination of catecholamines (norepinephrine, epinephrine, and dopamine) in various rat tissues. After alumina treatment of the tissue homogenate, catecholamines adsorbed on the alumina were dansylated by solid-phase reaction. Both the excess reagent and fluorescent degradation products produced during dansylation were washed out from the alumina. Dansylated catecholamines were eluted from the alumina and separated by reversed-phase high-performance liquid chromatography. The four catecholamine derivatives, including the internal standard, were separated within 17 min, and no major interfering peak could be detected on any chromatograms. The calibration graph showed a good linearity in a range of 10 to 500 pmol for each catecholamine per sample. This method was applied to different rat tissues, and both the recovery and the reproducibility for all samples proved to be satisfactory. The present study provides a simple, sensitive, and selective method useful for routine pharmacological experiments of the determination of catecholamines.