Emergency medical services (EMS) staff can play an important role in reducing emergency department (ED) overcrowding by decreasing unnecessary transfers. The present study was designed to evaluate the role of continuous education of EMS staff in decreasing the unnecessary transfers to ED. In this before-after study, analysis of 1500 EMS calls according to transferred and not transferred patients to ED was done and an educational package consisting of indications for transferring patients to ED based on existing references was prepared. EMS staff underwent an educational course by mentioned package and data of patients’ transportation after training was gathered and compared to the period before training. 3000 calls to pre-hospital emergency service were evaluated (1500 cases before and 1500 cases after training). The number of cases not transferred by EMS increased from 243 (16.2%) cases before training to 461 (30.7%) after that and the decreasing number of transfers to ED after training was significant (p<0.001). The highest percentage of decrease in transfer to ED belonged to complaints of lower back pain with 45%, mental problems with 27.7%, and direct extremity trauma with 23.4%, respectively. Patients not transferred to ED on the first call to EMS and coming with daily to ED during one week from the first call with the same complaint decreased from 13.6% (33 cases) to 8% (40 cases) after training. The highest percentage of the delayed coming patient to ED during 1 week after the first call to EMS belonged to cardiac complaints with 4.6% and mental complaints with 2.4%. Based on the findings of the present study, empowering pre-hospital emergency staff by continuous education leads to a 14.5% decrease in unnecessary referral cases and a 5.6% drop in unnecessary visits in ED.