Clinical relevance: Establishing the level of appropriateness and barriers to glaucoma care delivery by Australian optometrists are important first steps in developing tailored interventions aimed at improving glaucoma care delivery. Background: To determine the appropriateness of and barriers to glaucoma care by optometrists. Methods: A mixed method study was conducted. Phase I was a retrospective cross-sectional medical record audit that assessed glaucoma care appropriateness against 37 clinical indicators from a nationally representative sample of 42 optometry practices. In Phase II, focus groups and interviews involving 31 optometrists explored audit findings to identify barriers to appropriate glaucoma care. Barriers were analysed by deductive and inductive qualitative analysis. Saliency analysis was used to identify key domains that influence glaucoma care. Results: Appropriate glaucoma care was delivered for 63% (95% CI 61%, 64%) of the 420 patient encounters audited. Appropriate care was delivered above 80% for most (57%) indicators, while 14 (38%) indicators were delivered below 60% appropriateness. Good compliance to appropriate care was noted for key indicators of intraocular pressure measurement (90%, 95% CI 87%, 93%) and optic nerve head/retinal nerve fibre layer imaging (78%, 95% CI 74%, 82%). Important barriers identified were beliefs about expected outcomes, lack of perceived relevancy, time constraints, poor organisational culture, knowledge gaps, focusing on some aspects of glaucoma care to the detriment of others, the complexity of glaucoma care, information recall, and social norms. Conclusion: Glaucoma care was appropriate in most patient encounters, with opportunity to improve some aspects of history taking and physical examinations. Barriers to glaucoma care were diverse, existing at both the practitioner and organisational levels. These findings provide direction for the development of a tailored improvement intervention.