Endodontic access is the first mechanical step of root canal therapy, and its importance is often underestimated, that is, until something goes wrong. With proper case selection and risk assessment, it should be possible to minimize the risk of access-related complications. Recognition of the variables associated with complications, both tooth related and patient related, during the history and diagnosis phase is a critical element of prevention and successful treatment. The purpose of this chapter is to present some useful tools for risk assessment and describe strategies for successful endodontic access.