Retention behaviour of two pairs of 17-halogen-16,17-secoestra-1,3,5(10)-triene derivatives in RPLC was studied. Commercial column 5m- Spherisorb ODS-2, 124 × 4 mm was used. Mobile phase was acetonitrile-water in various proportions. Flow rate of mobile phase and column temperature varied. Correlation among various chromatographically obtained hydrophobicity parameters log kto and log kfro of 17-halogen-16,17-secoestra-1,3,5(10)-triene derivatives with log P, calculated by using commercial program ACD log P software Advanced Chemistry, Toronto, Canada was examined. The log kto and log kfro were obtained by linear extrapolation of retention of two pairs of 17-halogen-16,17-secoestra-1,3,5 (10)-triene derivatives to 0 of column temperature and to 0 of flow rate of the mobile phase.