BACKGROUND: Communication failure in prehospital emergency medicine can affect patient safety as it does in other areas of medicine as well. We analyzed the database of the critical incident reporting system for prehospital emergency medicine in Germany retrospectively regarding communication errors. METHODS: Experts of prehospital emergency medicine and risk management screened the database for verbal communication failure, non-verbal communication failure and missing communication at all. RESULTS: Between 2005 and 2015, 845 reports were analyzed, of which 247 reports were considered to be related to communication failure. An arbitrary classification resulted in six different kinds: 1) no acknowledgement of a suggestion; 2) medication error; 3) miscommunication with dispatcher; 4) utterance heard/understood improperly; 5) missing information transfer between two persons; and 6) other communication failure. CONCLUSION: Communication deficits can lead to critical incidents in prehospital emergency medicine and are a very important aspect in patient safety.