Dacryocystorhinostomy (DCR) is a procedure performed to drain the lacrimal sac in instances of nasolacrimal duct obstruction. It can be performed via an external incision or endoscopically. It is required when conservative dilation of the nasolacrimal duct fails. The external approach leaves a facial scar, and the procedure may be long and somewhat complicated, requiring the use of either the surgical microscope or loupes. Endoscopic DCR is a well-established alternative to the open procedure, permitting a success rate of 95%. Despite the added benefits afforded by the endoscopic technique, such as enhanced intranasal access to the lacrimal drainage system, there still exists a significant failure rate, particularly in revision procedures performed following a failed external DCR. In this review, the etiology, evaluation, and endoscopic surgical treatment of lacrimal obstruction is discussed.