Oral malodor was measured using a portable sulphide monitor in 2,672 individuals aged 18 to 64 years. In addition, dental (DMFT) and periodontal conditions (CPITN and attachment loss), dental plaque, and tongue coating status were assessed. Before clinical examination, subjects were interviewed about their oral health habits, smoking habits, and medical history. Data on volatile sulphur compounds (VSC) were analyzed by gender, age group, and time of measurement. There were no significant differences observed in the VSC between males and females in any age group. In each age group, the measured values of oral malodor were highest in the late morning group (58.6 ppb in average), followed by the late afternoon group (52.1 ppb), while lowest values were shown in the early afternoon group (39.4 ppb). Significant correlation was observed only between the VSC value and periodontal conditions and tongue coating status. The results also suggest that oral malodor might be caused mainly by tongue coating in the younger generation and by periodontal diseases together with tongue coating in older cohorts in the general population. Age was not a risk factor for increasing VSC.