Purpose: Oral glucose tolerance test (OGTT) is a very important procedure in diagnosing diabetes mellitus. It is very crucial to perform OGTT according to the rules that must be taken into account in preparation period of the test. Our aim was to determine the level of awareness and the source of information among the patients about the OGTT procedure.

Materials and Methods: The 680 outpatients, who were sent to the laboratory for OGTT, were asked to answer the questions reflecting the level of knowledge about OGTT. The data related to the answers to the questions were presented as numbers and ratios. Statistical analysis was made by chi square test.

Results: Only 160 (23.5%) of patients declared that they have got information about OGTT. The source of knowledge was mostly their clinicians 425 (62.5%) and the laboratory staff 255 (37.5%). According to the declaration of patients that they got information or not there was a statistically significant difference with the education level (p<0.05).

Conclusion: Although giving information to patients is the responsibility of the clinicians, the laboratory staff should try to understand if the patients are well informed or not, when giving OGTT appointment to the patients in order to complement insufficient information.