The prescription of preventive antibiotics in dental implant treatments reduces the incidence of early failures. This study has focused mainly on the influence of amoxicillin, which is contraindicated in penicillin-allergic patients. The present systematic review aimed to determine whether penicillin-allergic patients have a higher risk of implant failure compared to non-allergic patients. An electronic search was performed on Medline and Web of Science using the following MeSH terms: (penicillin allergy OR clindamycin OR erythromycin OR azithromycin OR metronidazole) AND (dental implant OR dental implant failure OR dental implant complications). The criteria employed were those described in the PRISMA® Declaration. Only five articles were included that analyzed the failure rates of implants placed in penicillin-allergic patients who were prescribed clindamycin compared to non-allergic patients who were prescribed amoxicillin. With the limitations of this study, it is not possible to state that penicillin allergy per se constitutes a risk factor for early dental implant failure as most of the studies included self-reported allergic patients. Clindamycin has been associated with a significantly elevated risk of failure and an up to six times increased risk of infection. Immediate implants also have a 5.7 to 10 times higher risk of failure.