A convenient solid phase method for extracting and fractionating steroid hormones from serum or urine is presented. The influence of the solvent used for extraction, of the body fluid to be extracted, and of the degree of sample dilution on the efficiency of extraction was studied for progesterone and cortisol. The potency of fractionation was demonstrated by the separation of the steroid pairs, deoxycortisol--cortisol and oestradiol--oestriol, from a urine sample. Influence of ionic strength, pH and temperature on the reproducibility was assessed for deoxycortisol in undiluted urine. With respect to practicability and efficiency, this method has proved to be considerably superior to conventional liquid-liquid techniques.