Iron deficiency is the most common nutritional deficiency in advanced cancer patients and causes anaemia. Iron deficiency anaemia treatment (i.e. intravenous or oral iron administration) has been demonstrated to be effective but is often associated with adverse reactions. Micronised microencapsulated ferric pyrophosphate (MMFP) is a recently developed formulation characterised by a higher intestinal bioavailability due to the small particle size distribution at nanometer level. The aim of this study was to evaluate the efficacy of an oral administration of 30 mg of MMFP associated with 80 mg of ascorbic acid in advanced cancer patients with hyposideraemia.This was an observational prospective cohort study (10 months) conducted on 42 adult patients with advanced cancer and serum iron levels lower than 60 μg/dL. All patients received one capsule/day for 30 days of a supplement containing 30 mg of MMFP and 80 mg of ascorbic acid. At enrolment (T0) and at 30 days (T1) patients were subjected to blood sampling for evaluation of serum iron, ferritinaemia and blood count. In addition, any undesirable effects reported by patients were evaluated.MMFP treatment increased sideraemia from 36.1±8.37 μg/dL to 73.22±28.60 μg/dL, haemoglobin from 10.43±1.09 g/dL to 11.52±1.90 g/dL, and ferritinaemia from 42.10±16.90 ng/mL to 123.33±55.79 ng/mL. No adverse effects were noted from the use of MMFP supplementation.The supplementation of 30 mg/d of MMFP in combination with 80 mg/d of ascorbic acid in advanced cancer patients with hyposideraemia led to a significant increase in sideraemia and ferritinaemia. Moreover, in some of the patients whose serum iron level did not increase, an increase in haemoglobin was observed.