A home-made carbon-nanotube paste electrode and multivariate standard-addition method by partial least square regression are employed to pursue improvement of analytical performance in differential pulse stripping voltammetry. Validation is achieved by analyzing reference standard solutions of Pb(II) and evaluating the control parameters: correlation coefficient, prediction coefficient, root-mean square error in calibration and root-mean square error in validation. Validation of multivariate calibration by external-standard method (interpolation) and partial least squares regression is obtained. Analogous validation is obtained also in extrapolation mode by multivariate standard addition method. Application to the analysis of drugs is described, showing the possibility to analyze complex matrices by the rapid, inexpensive and potentially multianalyte and portable voltammetric methodology here presented. (C) 2012 Elsevier B.V. All rights reserved.