Nortriptyline kinetics are compared between 10 Hispanic and 10 Anglo healthy, nondepressed volunteers matched for age, sex, and weight. All subjects were given a single oral dose of 75 mg of nortriptyline, and blood samples were drawn at various times over the next 96 hours. Nortriptyline concentration in plasma was determined by gas chromatography with nitrogen detector. From the nortriptyline concentration in plasma and time curve, various kinetic parameters were computed for each individual. There were large interindividual differences in various kinetic parameters. However, no statistically significant differences were found in any of the kinetic parameters between the Hispanic and Anglo groups. These results suggest that there are no major differences in pharmacokinetics and that purported hypersensitivity in Hispanic depressed patients to antidepressant treatment may be due to receptor hypersensitivity.