The purpose of the present work was to study some factors involved in renal handling of salt and water in the premenstrual syndrome (PMS), in which salt and water retention is frequently observed. In 18 women with PMS and in 18 healthy women we studied the levels of cyclic adenosine monophosphate, aldosterone, prostaglandin E2, prostaglandin F2 alpha and kallikrein in urinary samples collected during the luteal phase. There was no difference between the two groups regarding sodium, aldosterone and kallikrein urinary excretion. In the PMS group there was a significant reduction in urinary excretion of cyclic adenosine monophosphate, prostaglandin E2 and prostaglandin F2 alpha with respect to the control group. At multivariate analysis sodium urinary excretion proved not to be the same as the model validated in healthy women. There may be different renal handling of water and electrolytes during the luteal phase of the menstrual cycle in women with PMS.