Purpose: This paper investigates the moderating role of consumer involvement in the relationship between social media advertising and purchase intentions. Design/methodology/approach: A quantitative research design was employed, using survey data collected from 384 social media users aged 18 and above in Tamale, Ghana, who were exposed to social media advertising. Regression-based moderation analysis was conducted to examine the moderating effect of consumer involvement on the relationship between social media advertising and purchase intentions. Findings: The results indicate that social media advertising has a significant positive effect on purchase intentions. More importantly, consumer involvement significantly moderates this relationship, such that the influence of social media advertising on purchase intentions is stronger among highly involved consumers than among those with lower levels of involvement. Research limitations/implications: Although social media users in Ghana are numerous and diverse, the study was limited by its cross-sectional design, which prevents the establishment of causal relationships. Data were collected only in Tamale and relied on self-reported responses, which may affect accuracy. Therefore, generalizing the findings should be done with caution. Practical implications: The findings suggest that marketers should tailor social media advertising strategies to consumer involvement levels to enhance effectiveness. Highly informative and engaging content is particularly important for involved consumers. Originality/value: This study contributes to strategy and consumer behavior literature by empirically demonstrating the boundary condition of consumer involvement in explaining the effectiveness of social media advertising on purchase intentions.