Ranitidine ion-selective membrane electrodes were fabricated from PVC matrix and ranitidine hydrochloride (RNH-HCl)-phosphotungestic acid (PTA) as the detecting components in the existence of di-n-octyl phthalate (DOPH), di-n-butyl phthalate (DBPH) and dibutyl phosphate (DBP) as the solvent mediator and plasticizing the PVC membrane. The electrodes were prepared with DOPH (electrode 1), and DBPH (electrode 2) gave a Nernstian, stable, and rapid response, which displayed linear response in the concentration range of 1.0×10^-6-1.0×10^-2 mol.L^-1 and 2.03×10^-6-1.0×10^-2 mol.L^-1, with Nernstian slope of 58.73, and 52.50 mV.decade^-1 for electrode 1 and electrode 2 respectively. Limits of detection 9.30×10^-7 and 3.70×10^-7 mol.L^-1 for electrodes 1 and 2, respectively were also obtained. Individual electrodes were operative at the pH range of 3.0-5.5 and 3.5-5.5. The membrane electrodes showed excellent selectivity for the drug ranitidine in comparison with various inorganic cations. The electrodes showed a cycle of 55,50 days not including major variations in the parameters of the electrodes. Sensor 3 was given a non-Nernstian response equal to 28.76 mV.decade^-1 and the range of concentration was   2.0×10^-6-1.0×10^-2 mol.L^-1 with a limit of detection near 3.68×10^-7 mol.L^-1. Ranitidine can be determined effectively in unmixed and pharmaceutical formulations using these designated methods.