The relative lipophilicity, R M0 , and specific hydrophobic surface area of eleven 3-hydroxy-1,2-benzoisoxazoles substituted in the benzene ring (two isomeric fluoro, three isomeric chloro, three isomeric bromo and dibromo derivatives, and a nitro derivative) have been studied by reversed-phase thin layer chromatography (RP-TLC) on silica gel RP-C18 plates with methanol-water mixtures as mobile phases. Linear correlation between the volume fraction of methanol and R M values over a limited range was established with high correlation coefficients ( r > 0.99). Lipophilicity R M0 was compared with computed partition coefficients IAlogP, A logP s , clogP, milogP, logP KOWIN , and xlogP. The best correlation ( r > 0.9) was found between R M0 and logP KOWIN and xlogP values. Principal-components analysis (PCA) was also used to compare R M0 values with computed partition coefficients. The chromatographic behaviour of 3-hydroxy-1,2-benzisoxazoles was compared with that of their bioisosteric analogues 1,2-benzisot-iazolonoles. Experimental R M0 values for both groups of compounds were in accor-dance with the equation R M0 aR M0 +b(r> 0.9).