This study investigates the impact of disclosure prominence on the effectiveness of influencer advertising. Specifically, it examines the mediating roles of influencer trustworthiness in the causal relationship between disclosure prominence and purchase intention, and the moderating role of temporal distance from the point of purchase. The findings reveal that high disclosure prominence negatively affects both influencer trustworthiness and purchase intention. Moreover, temporal distance significantly moderates this relationship: the negative impact of disclosure prominence becomes stronger when the purchase is perceived as distant in time, whereas it is attenuated when the purchase is imminent. Additionally, temporal distance moderates the indirect effect of disclosure prominence on purchase intention via influencer trustworthiness. These findings contribute to the academic understanding of disclosure effects in influencer marketing and offer practical implications for tailoring disclosure strategies to align with consumers’ temporal proximity to the purchase decision—for instance, in campaigns targeting time-sensitive events such as anniversaries.