The aim of this study was to obtain periradicular tissue healing of a lateral root lesion using a microsurgical technique. The case report concerns a 52-year-old female patient, in general good health (ASA1), presented with the left maxillary canine (2.3) exhibiting acute, specific symptoms. A radiographic examination revealed the presence of a circumscribed radiolucent lesion associated with the mesial mid-root area of the 2.3 and the distal mid-root area of 2.2, both endodontically treated. Using an endoscope as a magnification device a surgical inspection of the middle-third of the root of 2.2 and 2.3 was made. A pathway between the periodontium and root-canal system was detected with an endodontic file on the middle-third of 2.3 root wall. A root-lateral cavity was prepared using retro-tips. An EBA cement was used as the root-end filling material. Following clinical and radiographic assessment at 36 months post-surgery, the case was classified as successful. This case report showed the utility of using an endoscope and micro-surgical instruments for diagnosis and surgical treatment of micro-anatomical root structures.