A molecularly imprinted polymer synthesized in dichloromethane, was evaluated for the selective extraction of a pharmaceutical compound from human plasma and integrated on-line with liquid chromatography. The target drug is an alpha-blocker called alfuzosin widely used for the treatment of benign prostatic hyperplasia. By a comprehensive approach of the retention mechanism, a selective extraction procedure was established by exploiting the development of electrostatic interactions between the target analyte and the selective support in LC compatible solvents. By applying this method to plasma, extraction recoveries close to 100% were obtained for alfuzosin while various pharmaceutical compounds currently found in biological fluids were not retained on the support. The high selectivity of the support coupled to the chromatographic system permitted an easy and fast analysis of the drug with a limit of quantification of 15 microg L(-1) by UV detection.