PURPOSE: To evaluate the efficacy of azithromycin hydrate ophthalmic solution for the treatment of internal hordeolum and meibomitis with or without phlyctenular keratitis. STUDY DESIGN: Retrospective study. METHODS: Patients diagnosed with internal hordeolum or meibomitis were prescribed azithromycin hydrate ophthalmic solution twice daily for 2 days and then once daily for 12 days. Depending on the presence of meibomitis-related keratoconjunctivitis (MRKC), we further divided the patients with meibomitis into three subgroups: meibomitis alone (non-MRKC group), meibomitis with non-phlyctenular MRKC (non-phlyctenular group), and meibomitis with phlyctenular MRKC (phlyctenular group). Inflammatory findings (eyelid redness and conjunctival hyperemia) were scored before and after treatment. Some patients also underwent culture testing fluids discharged by the meibomian gland orifices. RESULTS: Three patients (3 eyes) had internal hordeolum and 16 patients (16 eyes) had meibomitis. After treatment, the inflammatory findings disappeared in all eyes with internal hordeolum. Among the patients with meibomitis, three eyes were in the non-MRKC, six in the non-phlyctenular, and seven in the phlyctenular group. The inflammatory findings were significantly improved only in the phlyctenular group. Among seven eyes with positive culture results, Cutibacterium acnes was detected in five, and treatment improved the inflammatory findings in all of these eyes. CONCLUSION: Azithromycin hydrate ophthalmic solution is effective for the treatment of inflammatory meibomian gland diseases, including internal hordeolum and meibomitis. In particular, the agent is highly efficient in patients with phlyctenular MRKC.