Heterocyclic oxime ethers play a significant role in organisms due to their biological activity. Lipophilicity is an important parameter that may affect biological activity of the compounds 1-(benzofuran-2-yl)ethan-1-one oxime and its nine biologically active ethers. The relationship between the structure and lipophilicity parameters (log kw values) of the ten compounds is here described. Reversed phase high performance liquid chromatography (RP-HPLC) method was used having methanol, 2-propanol and acetonitrile as organic modifiers of the mobile phases. Both experimental (log kw) and calculated (log P) parameters showed to be strongly positively correlated. The weakest correlation with all the data was for the log kw methanol. For all of analyzed compounds, log kw values are smaller than 5 (except for analyses carried out in methanol), and this result corresponds to the Lipinski’s rule in the range of lipophilicity. Therefore, in the case of their use as drugs, they will be probably active after oral application.