Primaquine reacts with diszo-p-nitroaniline in acid medium to give an orange yellow colour having and absorption maximum at 478 nm. On rendering the medium alkaline, a bathochromic ahift acompanied by hypochromic effect was revealed; the new maximum is located at 525 nm. The mean percentage recoveries for authentic samples amout to 100+, and 100.21+, 0.9 by the acid and alkaline procedures respectively, (p=0.05). Both methods could be applied to determine primaquine salts in pharmaceutical preparatins; the results obtained were in good agreement with those of the offictial method.