The accumulation/voltammetric behavior of the tricyclic antidepressant imipramine (Imip) was investigated at a fatty acid modified carbon paste electrode This hydrophobic drug accumulated onto the electrode surface, then was stripped by scanning the potential toward the positive direction. The oxidation peak response showed a great enhancement on using the modified electrode over the unmodified one. The peak current was examined with respect to preconcentration time, pH, paste composition, reproducibility, possible interferences and other variables. The response is linear over the range from 0.1 to 8.0 μM (r = 0.9980), after 3 minutes stirring time, using phosphate (0.1 M) pH 9. A detection limit of 0.001 μM was obtained. The method was applied to the pharmaceutical formulation Tofranil and to the biological samples.