Atenolol selective electrodes were prepared based on a complex atenolol-phosphotungstate as an active material using the plasticizers di-butyl phosphate (DBP), tri-butyl phosphate (TBP), o-nitro phenyl octyl ether (NPOE) and di-octyl phthalate (DOPH) in a PVC matrix membrane. The properties of the prepared electrodes were studied, namely slope, concentration range, detection limit, lifetime, pH effect and selectivity. The experimental results showed that the best electrode was based on DOPH as plasticizer, displaying a linear range from 1.00 x 10(-4) M to 5.00 x 10(-2) M with a Nernstian slope of 55.91 mV/decade and correlation coefficient of 0.9995. The detection limit was 5.00 x 10(-5) M and the lifetime was around 90 days. The proposed electrode was successfully applied to the determination of atenolol in a pharmaceutical preparation. The average recovery for atenolol determination in tablets was around 98.50%, with standard deviation +/- 0.1.