Real-life studies offer the opportunity of obtaining outcomes suitable in clinical practice, as controlled trials do not mirror the real patients' population observed in clinical practice. This concept is particularly appropriate for allergen immunotherapy (AIT). Therefore, the current review will present and discuss the most recent and relevant studies published on this topic. Globally, 15 real-life studies on AIT efficacy are available until now, the total of patients amounts to 9090, with an average number of 699 patients per study. This high number significantly decreases the possibility that the observations from real-life study are casual, and confers to such studies a key role in the next years to assess issues other than efficacy and safety, especially those scantly investigated thus far.sessed by meta-analyses, but the validity and applicability of the observations resulting from RCTs data, especially in the context of real-life settings, is debatable (5). To confirm the applicability to common practice of AIT products demonstrated as effective in RCTs, real-life (also defined real-world) studies are needed. This model was increasingly used in recent years and, especially when based on large populations of patients, provides very useful data to optimize the prescription and the performance of AIT in clinical practice. Here, we will discuss the significance of the outcomes that were achieved in such studies.