Fecal microbiota transplantation (FMT) has proven to be very effective in recurrent Clostridium difficile infection (CDI) when compared with standard antibiotic therapy. However, given the lack of validated criteria, decision regarding number and timing of infusions is currently based on the clinician's experience, severity of infection, and clinical response. We performed a longitudinal assessment of fecal calprotectin concentration (FCC) in CDI patients undergoing FMT. FCCs were correlated with the need for multiple infusions and with the clinical status of the patient. Fecal calprotectin concentration measurement was performed just before first procedure (T0 ) and 2 (T1 ) and 5 (T2 ) days later. The need for reinfusion was accounted for in the 8weeks following procedure, and clinical status was evaluated at the end of the given period. Both outcomes were correlated with measured FCCs. A total of 28 CDI patients undergoing FMT were enrolled. Median FCCs at T0 were significantly higher in patients who needed repeat FMT, 540μg/g versus patients who underwent single FMT, 290μg/g (P<0.05). Differences were not significant for FCC at T1 and T2 . Regarding correlation with clinical outcome, median FCC at T0 was found to be lower in responders compared with non-responders with a trend towards statistical significance (P=0.07). Correlation at T1 and T2 was not significant. The use of an easily obtainable parameter such as fecal calprotectin could possibly optimize overall management of FMT procedural framework potentially being able to immediately identify patients who may benefit from repeat infusions.