A survey within Italian haematopoietic stem cell transplant (HSCT) programmes was performed, in order to obtain a snapshot of nutritional support (NS) in patients undergoing HSCT. The primary objective was to verify whether an evidence-based practice (EBP) approach to NS was implemented in HSCT centres. A multicentre survey was performed by questionnaire, covering the main areas of NS (screening, treatment planning, monitoring, nutritional counselling, and methods of nutritional support). The results indicated a significant variation between clinical practice and evidence-based guidelines in terms of clinical pathways, decision-making, and care provision regarding NS. Further research is required to identify reasons for the limited application of EBP and measures that may be undertaken to address such issues. Development of a multidisciplinary educational programme in order to raise awareness of the issue should be undertaken.