Consumer brand engagement (CBE) signals propensity for brand purchase. A scale proposes three dimensions of CBE (i.e., cognitive, affective and activation dimensions) but the dimensions prominent and driving brand purchase intentions in an Instagram cosmetic purchase context need examination. In this context, this study tests Hollebeek, Glynn and Brodie’s (2014) 10-items/3 dimensions scale and examines an outcome of cosmetics brand purchase intention on Instagram. Data was quantitatively collected from 203 consumers who were students and non-students using convenience and snowballing non- probability sampling method. Confirmatory factor analysis and structural equation modelling were used to analyse the data. The results revealed that although the three CBE dimensions were identified in a Cosmetic Instagram purchase context, it was the affective and activation dimensions that positively predicted consumers’ intentions to purchase cosmetic brands after engaging with the brand on Instagram. Theoretical and practical implications are provided.