Purpose: To evaluate the diagnosis of halitosis in relation to the oral malodour judge's experience, age, gender and calibration. Materials and Methods: This study included 38 dental patients who volunteered to participate. Patients were evaluated for halitosis by 6 clinicians using the organoleptic method and by measuring mouth exhaled air using a halimeter, which is considered the gold standard. Sensitivity, specificity, and positive and negative predictive values were calculated for each clinician. Consistency between clinicians was evaluated through a kappa test. Significance level was set at P 0.05. Results: Out of the 38 patients, 14 were diagnosed with halitosis by 6 clinicians using a halimeter. The highest sensitivity (89%) was found for clinician No. 6, followed by clinician No. 5 (78%). Specificities were 57% for clinician No. 4 and 36% for clinician No. 1 and No. 5. The most correct positive predictive value (halitosis according to halimeter readings) was made by clinician No. 6 (65%), who also had the highest rates (83%) of negative predictive value (no halitosis according to halimeter readings). There were no statistically significant differences (P > 0.05) between the diagnoses of clinicians No. 1, 2, 3, 5, or 6; however, the diagnoses made by clinician No. 4 were statistically different (P 0.05) than those of all other clinicians. The highest rate of agreement (44%) in diagnoses was between the two calibrated clinicians. However, there was no correlation between the halitosis diagnoses and the age, gender and years of experience of the clinicians. Conclusions: This study indicates that calibration of clinicians is a significant factor in the organoleptic evaluation of halitosis. Keywords: bad breath, halitosis, oral clinician's calibration, organoleptic method