This study explored the factor structure and reliability of a new Health Behaviour Inventory (HBI) to assess the health behaviour of adults. Data in this study were collected from a total of 581 postgraduate students of the University of Cape Coast. The HBI was subjected to principal component factor analysis with Varimax (Kaiser Normalization). The Kaiser Meyer–Olkin measure was used to verify the sampling adequacy for the factor analysis, which yielded KMO of .808. This indicated that the sample size was adequate and factor analysis could be performed on the data set. Bartlett’s test of Sphericity (χ2 = 8133.626, p = 0.000) was significant for the sample. The analysis yielded six factors with robust reliabilities. The six factors were: alcohol intake, smoking, dietary behaviour, physical exercise, salt intake and weight management. With respect to the reliability of the instrument, the HBI items yielded a Cronbach’s alpha of .792 for the total scale. The exploratory factor analyses demonstrated good factor structure and internal consistency. However, since this is the first study to explore the HBI structure, the researchers recommended that further investigations into the psychometric properties (such as the predictive validity) of the instrument be carried out.