The objective of this paper is to review the main findings of the largest studies on the etiopathogenesis and microbiology of the development of dacryocystitis and to formulate clinical and surgical guidelines based on said studies and on our experience at Cruces Hospital, the Basque Country, Spain. The most common sign of this entity is the distal nasolacrimal duct obstruction, and this should be treated to prevent clinical relapse. The time when surgery should be indicated mainly depends on the clinical signs and symptoms, age and general status of a patient. Given the germs isolated in cases of dacryocystitis, antibiotic therapy against Gram positive (S. aureus, S. pneumoniae, S. epidermidis) and Gram negative bacteria (H. influenzae, P. aeruginosa) should be administered, orally in adults and intravenously in pediatric patients, prior to surgery. Gentamicin and amoxicillin-clavulanic acid have been found to be effective against the bacteria commonly implicated in the etiopathogenesis of this entity.