In 2011 the Reciproc System was introduced to the market by VDW (Munich, Germany) as a single file reciprocating system. It is claimed that root canals can be completely prepared with only one Reciproc instrument. This case series describes the treatment of four teeth needing root canal treatment by using the Reciproc System. The illustrated cases show that root canal treatment as well as endodontic retreatment can be safely carried out with Reciproc instruments. Schlagwörter: NiTi, reciprocating technique, Reciproc, root canal treatment