Alkali metal ion sensitive membranes of plasticized poly(vinyl chloride) (PVC) were prepared by an inkjet printer, and a 128 × 128 (16K) pixel array multi-ion image sensor that simultaneously imaged sodium and potassium ions was developed. The basic sensor chip fabricated from a charge coupled device (CCD) and complimentary metal-oxide semiconductor (CMOS) was used. The sodium-ion-sensitive membrane prepared by an inkjet printer was characterized by comparing the membranes made by conventional casting. The sodium ion membrane made by the inkjet printer had a limited area and thickness, and exhibited a near Nernstian response in 10–20 µm thickness. The multi-ion image sensor with two kinds of ion-sensitive plasticized PVC membrane was also prepared on the same sensor chip. When 10 mM of sodium ion solution was added into the sample solution of equal volume including 0.1 mM of sodium ions, the region of the sodium-ion-sensitive membrane displayed a large potential change but the region of the potassium-ion-sensitive membrane had no response to the concentration change. When 10 mM of potassium ion solution was added into the sample solution of equal volume including 0.1 mM of potassium ions, the region of the potassium-ion-sensitive membrane displayed a large potential change but the sodium-ion-sensitive membrane did not show a significant change. The 16K array CCD multi-ion imaging sensors with a finely striped pattern to monitor sodium and potassium ions functioned successfully.