To identify specific items on knowledge and need for information that could be used to improve compliance with glaucoma medication. Forty-four randomly selected ophthalmologists assigned 166 consecutive glaucoma patients to complete a questionnaire. The questionnaire was developed systematically based on focus group interviews, consultation of experts and a pilot test. Items included knowledge about glaucoma and its treatment, need for information and compliance with therapy. No statistically significant correlation was found between the total level of knowledge and compliance. Concerning knowledge of glaucoma, one out of 19 items had a statistically significant negative correlation with compliance. Concerning knowledge of glaucoma treatment, one out of 18 items had a statistically significant positive correlation with compliance. Regarding total need for information, no statistically significant correlation with compliance was found. Three out of 22 items had a statistically significant positive correlation with compliance. Given the number of related items, their direction and limited strength of correlation and the difficulty of hypothesizing a causal relation for some items, it is unlikely that further improving knowledge will greatly improve compliance with glaucoma medication. Interventions focused on attitude and discipline may be of more benefit in improving compliance with therapy.