Objectives: Common complications associated with dental implant surgery are well recognized and are usually explained to patients during the process of informed consent. For the general dental practitioner, the periodontist, and the oral and maxillofacial surgeon, it is relevant to also be familiar with less frequent complications. This review gathers unusual complications of this surgical procedure and presents unique complications from single case reports. Method and Materials: Studies were located using systematic searches in Medline and the Cochrane Library electronic databases. Key words included the terms "implant", "dental", "oral", "complication", "unusual", and "rare". References from the relevant articles were also double-checked. The review was limited to English and German language articles, published within the last 15 years. Results: 17 different unusual complications were identified. The majority of studies report five different complications: permanent nerve injury, damage to teeth adjacent to the implant, excessive bleeding resulting in hematoma of the floor of the mouth, mandibular fracture, and displacement of implants into the maxillary sinus. Benign paroxysmal positional vertigo and a plunging ranula were reported sporadically. Another 10 complications were only described once in our literature search. Conclusion: Unusual complications are challenging. It is important for the dental practitioner to be aware of all the possible complications and to recognize them early so that adequate therapy can immediately be ensured. Keywords: complications, dental implants, rare