AbstractData for 216 partition coefficients in propylene glycol dipelargonate (PGDP) are given, along with 80 derived fragment values and a scheme for calculating the p.e. 2 correction from which many more logPvalues can be derived. PGDP logPandf‐values are contrasted with those of octanol and discussed in terms of the differing balance of proton donor/acceptor properties which these solvents show. It is suggested that PGDP, in conjunction with octanol, can be used as a model solvent probe for membrane binding and transport characteristics in ways that may have special relevance to biological selectivit