The effect of grapefruit phenols on utilization of some minerals (Ca, P, Mg, Zn, Cu and Fe) in rats was examined. Lyophilised extract from hard parts of grapefruit (stone, peel, white coats) containing mainly flavonones (naringin, hespereridin, hesperetin, nairutin, neohesperedin) was introduced into casein diets in the amount of 0.1% and 0.4% (group C-0.1 and C-0.4, respectively). The addition of tested preparation modified mineral availability to a different extent. No differences in Ca retention between control group (42.72 mg/day) and groups C-0.1 and C-0.4 (40.9 and 43.54 mg/day, respectively) were observed. Compared to control group, retention of P increased from 25.94 mg/day to 42.92 and 44.39; retention of Mg from 2.3 mg/day to 3.55 and 4.15; retention of Zn from 41 µg/day to 96 and 150; retention of Cu from 55.4 µg/day to 64.2 and 71.7 in groups C-0.1 and C-0.4 respectively. Simultaneously, a dose-dependent reduction of Fe retention was observed from 1 µg/day in control group to -39 µg/day in group C-0.1 and -102 µg/day in group C-0.4. However, a 0.1% addition caused only insignificant decrease in retention of this mineral. The results obtained indicate that small amounts of grapefruit polyphenols in diets can improve availability of some minerals without significant negative influence on Fe status.