PURPOSE: To compare the conjunctival, lacrimal sac, and nasal flora cultures and conjunctival normalization time following external (EX-), endoscopic (EN-), and transcanalicular multidiode laser (TC-) dacryocystorhinostomy (DCR) and to evaluate the relationship between culture positivity and surgical success. We further performed antibiotic sensitivity analyses for lacrimal sac culture samples. METHODS: A total of 90 patients with primary acquired nasolacrimal duct obstruction were recruited and divided into EX-DCR (n=32), EN-DCR (n=28), and TC-DCR (n=30) groups. Conjunctival, nasal, and lacrimal sac cultures and antibiograms were analyzed. RESULTS: In all three groups, coagulase-negative Staphylococcus (CNS) was predominantly isolated preoperatively from the conjunctiva, nose, and lacrimal sac and postoperatively from the conjunctiva. Preoperative and postoperative conjunctival culture positivity rates were similar between all the groups (p>0.05). A statistically significant difference in the growth rate of culture in the lacrimal sac was observed between the three groups (p=0.001). CNS and Staphylococcus aureus cultures were predominantly sensitive to linezolid, teicoplanin, tigecycline, vancomycin, and mupirocin. Conjunctival normalization times were similar between the three groups (p>0.05). Anatomical and functional success rates were not found to be significantly correlated with preoperative conjunctival and lacrimal sac culture positivity (p>0.05). CONCLUSIONS: Similar rates of preoperative and 1-week postoperative conjunctival culture positivity were observed in all the groups; a significantly lower bacterial growth rate was observed in postoperative conjunctival cultures. CNS was the most commonly isolated organism. Bacterial growth rates in the lacrimal sac samples were significantly higher in the EN-DCR group. Bacterial growth rates obtained preoperatively from the conjunctival and lacrimal sac culture samples were not correlated with DCR success.