Four stereoisomers of inositol p-aminosalicylate, that is hexaris-O-(p-aminosalicylyl)-myo-inositol, hexaris-O-(p-aminosalicylyl)-muco-inositol were synthesized by p-aminosalicylyl chloride with myo-, epi-, scyllo-, and muco-inositol respectively. Their antibacterial activity was tested against human type tubercle bacilli $H_{37}$/Rv, in contrast to 1.25.gamma./ml of p-aminosalicylic acid used as control. Hexaris-O-(p-aminoslicylyl)-muco-inositol showed the strongest antibacterial action at 0.625.gamma./ml, the other compounds more or less active than p-aminosalicylic acid.